# SMTP Component The SMTP Component is used to send internet mail using the SMTP protocol (the internet mail standard). ## Syntax ```text nsoftware.IPWorksEDI.SMTP ``` ## Remarks The SMTP Component supports both plaintext and Secure Sockets Layer/Transport Layer Security (SSL/TLS) connections (RFC 2487). When connecting over Secure Sockets Layer/Transport Layer Security (SSL/TLS) the [SSLServerAuthentication](#sslserverauthentication-event-smtp-component) event allows you to check the server identity and other security attributes. The [SSLStatus](#sslstatus-event-smtp-component) event provides information about the SSL handshake. Additional SSL-related settings are also supported through the [Config](#config-method-smtp-component) method. The SMTP Component implements a standard SMTP client as specified in RFC 821. It has a simple plug-and-play interface. It contains a number of properties, such as [SendTo](#sendto-property-smtp-component), [Subject](#subject-property-smtp-component), [From](#from-property-smtp-component), [Cc](#cc-property-smtp-component), and [BCc](#bcc-property-smtp-component), that map directly to the internet mail message headers with the same name (RFC 822). The message text is set in [MessageText](#messagetext-property-smtp-component). Messages are sent by calling the [Send](#send-method-smtp-component) method. The component supports message delivery to multiple recipients through the [SendTo](#sendto-property-smtp-component), [Cc](#cc-property-smtp-component), and [BCc](#bcc-property-smtp-component) properties. Simply specify the destination email addresses separated by commas. The interface of the component is open-ended. New features, including MIME attachments, can be supported by using the [OtherHeaders](#otherheaders-property-smtp-component) property. A number of events provide feedback during the operation of the component. The [Transfer](#transfer-event-smtp-component) event is fired during message delivery to show the number of bytes delivered. The [PITrail](#pitrail-event-smtp-component) event traces the commands that are sent to the server and the respective replies. ## Property List *The following is the full list of the properties of the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [AllowExtensions](#allowextensions-property-smtp-component) | This property is a switch allowing the component to use ESMTP features (Extended SMTP). | | [AuthMechanism](#authmechanism-property-smtp-component) | This property is used when connecting to the mail server. | | [BCc](#bcc-property-smtp-component) | This property includes a comma-separated list of addresses for blind carbon copies (optional). | | [Cc](#cc-property-smtp-component) | This property includes a comma-separated list of addresses for carbon copies (optional). | | [Connected](#connected-property-smtp-component) | Whether the component is connected. | | [DeliveryNotificationTo](#deliverynotificationto-property-smtp-component) | This property includes the email address to which to send a delivery notification. | | [Firewall](#firewall-property-smtp-component) | A set of properties related to firewall access. | | [From](#from-property-smtp-component) | This property includes the email address of the sender (required). | | [Idle](#idle-property-smtp-component) | The current status of the component. | | [Importance](#importance-property-smtp-component) | This property indicates the importance of the mail message (optional). | | [LastReply](#lastreply-property-smtp-component) | This property indicates the last reply received from the server. | | [LocalHost](#localhost-property-smtp-component) | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. | | [MailPort](#mailport-property-smtp-component) | This property includes the server port for SMTP (default 25). | | [MailServer](#mailserver-property-smtp-component) | This property includes the name or address of a mail server (mail relay). | | [Message](#message-property-smtp-component) | This property provides a way to set the raw message content. | | [MessageDate](#messagedate-property-smtp-component) | This property includes the date of the mail message (optional). | | [MessageHeaders](#messageheaders-property-smtp-component) | This property includes a collection of RFC 822-encoded headers of the message. | | [MessageHeadersString](#messageheadersstring-property-smtp-component) | This property includes the string representation of RFC 822-encoded headers of the message. | | [MessageId](#messageid-property-smtp-component) | This property includes the message identifier for the message. | | [MessageRecipients](#messagerecipients-property-smtp-component) | This property includes the collection of recipients of the message. | | [MessageText](#messagetext-property-smtp-component) | This property includes the full text of the message to send (without headers). | | [OAuth](#oauth-property-smtp-component) | The OAuth settings. | | [OtherHeaders](#otherheaders-property-smtp-component) | This property includes an RFC 822-compliant string consisting of extra headers. | | [Password](#password-property-smtp-component) | This property includes a password for logon to the [MailServer](#mailserver-property-smtp-component) . | | [Priority](#priority-property-smtp-component) | This property includes the priority of the mail message (optional). | | [ReadReceiptTo](#readreceiptto-property-smtp-component) | This property includes the email address to send a read-receipt to. | | [ReplyTo](#replyto-property-smtp-component) | This property includes a mail address to which to reply (optional). | | [ReturnPath](#returnpath-property-smtp-component) | This property sets the Return-Path to be used for sending email. | | [SendTo](#sendto-property-smtp-component) | This property includes a comma-separated list of addresses for destinations (required). | | [Sensitivity](#sensitivity-property-smtp-component) | This property indicates the sensitivity of the mail message (optional). | | [SSLAcceptServerCert](#sslacceptservercert-property-smtp-component) | Instructs the component to unconditionally accept the server certificate that matches the supplied certificate. | | [SSLCert](#sslcert-property-smtp-component) | The certificate to be used during Secure Sockets Layer (SSL) negotiation. | | [SSLEnabled](#sslenabled-property-smtp-component) | This property indicates whether Transport Layer Security/Secure Sockets Layer (TLS/SSL) is enabled. | | [SSLProvider](#sslprovider-property-smtp-component) | The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. | | [SSLServerCert](#sslservercert-property-smtp-component) | The server certificate for the last established connection. | | [SSLStartMode](#sslstartmode-property-smtp-component) | This property determines how the component starts the Secure Sockets Layer (SSL) negotiation. | | [Subject](#subject-property-smtp-component) | This property includes the subject of the mail message (optional). | | [Timeout](#timeout-property-smtp-component) | The timeout for the component. | | [User](#user-property-smtp-component) | This property includes the user identifier needed to log in as in the [MailServer](#mailserver-property-smtp-component) . | ## Method List *The following is the full list of the methods of the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [Config](#config-method-smtp-component) | Sets or retrieves a configuration setting. | | [Connect](#connect-method-smtp-component) | This method connects to the mail relay and sends the SMTP HELO command. | | [Disconnect](#disconnect-method-smtp-component) | This method disconnects from the SMTP server. | | [DoEvents](#doevents-method-smtp-component) | This method processes events from the internal message queue. | | [Expand](#expand-method-smtp-component) | This method asks the [MailServer](#mailserver-property-smtp-component) to expand a name or mailing list. | | [Interrupt](#interrupt-method-smtp-component) | This method interrupts the current method. | | [ProcessQueue](#processqueue-method-smtp-component) | This method sends the messages that previously have been queued into QueueDir . | | [Queue](#queue-method-smtp-component) | This method queues the message into QueueDir . | | [Reset](#reset-method-smtp-component) | This method will reset the component. | | [ResetHeaders](#resetheaders-method-smtp-component) | This method resets all the message headers to empty. | | [Send](#send-method-smtp-component) | This method sends the current message. | | [SendCommand](#sendcommand-method-smtp-component) | This method sends the exact command directly to the server. | | [SendToTerminalAndEmail](#sendtoterminalandemail-method-smtp-component) | This method sends to terminal and email. | | [SendToTerminalOnly](#sendtoterminalonly-method-smtp-component) | This method sends to terminal only. | | [SendToTerminalOrEmail](#sendtoterminaloremail-method-smtp-component) | This method sends to terminal or email. | | [SetMessageStream](#setmessagestream-method-smtp-component) | This method sets the stream to be uploaded to the server as part of the message. | | [Verify](#verify-method-smtp-component) | This method sends a verification request to the SMTP server. | ## Event List *The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [ConnectionStatus](#connectionstatus-event-smtp-component) | Fired to indicate changes in the connection state. | | [EndTransfer](#endtransfer-event-smtp-component) | This event is fired when the message text completes transferring. | | [Error](#error-event-smtp-component) | Fired when information is available about errors during data delivery. | | [Expand](#expand-event-smtp-component) | This event is fired for every email address returned by the server when the [Expand](#expand-method-smtp-component) method is called. | | [LaunchBrowser](#launchbrowser-event-smtp-component) | Fires before launching a browser with the authorization URL. | | [Log](#log-event-smtp-component) | Fired once for each log message. | | [PITrail](#pitrail-event-smtp-component) | This event traces the commands sent to the mail server, and the respective replies. | | [SSLServerAuthentication](#sslserverauthentication-event-smtp-component) | Fired after the server presents its certificate to the client. | | [SSLStatus](#sslstatus-event-smtp-component) | Fired when secure connection progress messages are available. | | [StartTransfer](#starttransfer-event-smtp-component) | This event is fired when the message text starts transferring. | | [Transfer](#transfer-event-smtp-component) | This event is fired when the message text is transferred to [MailServer](#mailserver-property-smtp-component) . | ## Config Settings *The following is a list of config settings for the component with short descriptions. Click on the links for further details.* | | | | --- | --- | | [AllowEmptyTo](#AllowEmptyTo) | If set to True, then the SendTo property is not required. | | [AuthorizationIdentity](#AuthorizationIdentity) | The value to use as the authorization identity when SASL authentication is used. | | [Charset](#Charset) | When set, the message headers will be encoded using the specified Charset. | | [FoldHeaders](#FoldHeaders) | Tells the component whether to fold the headers. | | [Hello](#Hello) | The argument for HELO (herald) command to the server (defaults to local host name). | | [KeepQueue](#KeepQueue) | If set to True, queued files are not deleted after a successful send. | | [MaxHeaderLength](#MaxHeaderLength) | Maximum length for headers to avoid line folding (default 80). | | [MessageHeadersString](#MessageHeadersString) | String representation of RFC822-encoded headers of the message. | | [MessageIdAlgorithm](#MessageIdAlgorithm) | Determines the algorithm used to hash the random MessageId. | | [OtherHeaders](#OtherHeaders) | An RFC 822 compliant string consisting of extra headers. | | [ReturnPath](#ReturnPath) | Sets the Return-Path to be used for sending email. | | [SendRSET](#SendRSET) | Whether to send RSET command. | | [StopOnBccErrors](#StopOnBccErrors) | Instructs the component to stop sending the message if the server does not acknowledge any of the BCCs. | | [StopOnCcErrors](#StopOnCcErrors) | Instructs the component to stop sending the message if the server does not acknowledge any of the CCs. | | [StopOnToErrors](#StopOnToErrors) | Instructs the component to stop sending the message if the server does not acknowledge any of the TOs. | | [TransferText](#TransferText) | String representation of RFC822-encoded body of the message. | | [CloseStreamAfterTransfer](#CloseStreamAfterTransfer) | If true, the component will close the upload or download stream after the transfer. | | [ConnectionTimeout](#ConnectionTimeout) | Sets a separate timeout value for establishing a connection. | | [EnableFallback](#EnableFallback) | Whether to try the other addresses the remote host resolves to when a connection attempt fails. | | [FallbackTimeout](#FallbackTimeout) | The maximum time in milliseconds to spend on connection attempts when EnableFallback is enabled. | | [FirewallAutoDetect](#FirewallAutoDetect) | Tells the component whether or not to automatically detect and use firewall system settings, if available. | | [FirewallHost](#FirewallHost) | Name or IP address of firewall (optional). | | [FirewallHTTPVersion](#FirewallHTTPVersion) | The HTTP version to be used when connecting through a tunneling proxy. | | [FirewallListener](#FirewallListener) | If true, the component binds to a SOCKS firewall as a server (TCPClient only). | | [FirewallPassword](#FirewallPassword) | Password to be used if authentication is to be used when connecting through the firewall. | | [FirewallPort](#FirewallPort) | The TCP port for the FirewallHost;. | | [FirewallType](#FirewallType) | Determines the type of firewall to connect through. | | [FirewallUser](#FirewallUser) | A user name if authentication is to be used connecting through a firewall. | | [KeepAliveInterval](#KeepAliveInterval) | The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received. | | [KeepAliveTime](#KeepAliveTime) | The inactivity time in milliseconds before a TCP keep-alive packet is sent. | | [Linger](#Linger) | When set to True, connections are terminated gracefully. | | [LingerTime](#LingerTime) | Time in seconds to have the connection linger. | | [LocalHost](#LocalHost) | The name of the local host through which connections are initiated or accepted. | | [LocalPort](#LocalPort) | The port in the local host where the component binds. | | [MaxLineLength](#MaxLineLength) | The maximum amount of data to accumulate when no EOL is found. | | [MaxTransferRate](#MaxTransferRate) | The transfer rate limit in bytes per second. | | [ProxyExceptionsList](#ProxyExceptionsList) | A semicolon separated list of hosts and IPs to bypass when using a proxy. | | [TCPKeepAlive](#TCPKeepAlive) | Determines whether or not the keep alive socket option is enabled. | | [TcpNoDelay](#TcpNoDelay) | Whether or not to delay when sending packets. | | [UseIPv6](#UseIPv6) | Whether to use IPv6. | | [UseNTLMv2](#UseNTLMv2) | Whether to use NTLM V2. | | [CACertFilePaths](#CACertFilePaths) | The paths to CA certificate files when using Mono on Unix/Linux. | | [LogSSLPackets](#LogSSLPackets) | Controls whether SSL packets are logged when using the internal security API. | | [ReuseSSLSession](#ReuseSSLSession) | Determines if the SSL session is reused. | | [SSLCACerts](#SSLCACerts) | A newline separated list of CA certificates to be included when performing an SSL handshake. | | [SSLCheckCRL](#SSLCheckCRL) | Whether to check the Certificate Revocation List for the server certificate. | | [SSLCheckOCSP](#SSLCheckOCSP) | Whether to use OCSP to check the status of the server certificate. | | [SSLCipherStrength](#SSLCipherStrength) | The minimum cipher strength used for bulk encryption. | | [SSLClientCACerts](#SSLClientCACerts) | A newline separated list of CA certificates to use during SSL client certificate validation. | | [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) | The cipher suite to be used in an SSL negotiation. | | [SSLEnabledProtocols](#SSLEnabledProtocols) | Used to enable/disable the supported security protocols. | | [SSLEnableRenegotiation](#SSLEnableRenegotiation) | Whether the renegotiation_info SSL extension is supported. | | [SSLIncludeCertChain](#SSLIncludeCertChain) | Whether the entire certificate chain is included in the SSLServerAuthentication event. | | [SSLKeyLogFile](#SSLKeyLogFile) | The location of a file where per-session secrets are written for debugging purposes. | | [SSLNegotiatedCipher](#SSLNegotiatedCipher) | Returns the negotiated cipher suite. | | [SSLNegotiatedCipherStrength](#SSLNegotiatedCipherStrength) | Returns the negotiated cipher suite strength. | | [SSLNegotiatedCipherSuite](#SSLNegotiatedCipherSuite) | Returns the negotiated cipher suite. | | [SSLNegotiatedKeyExchange](#SSLNegotiatedKeyExchange) | Returns the negotiated key exchange algorithm. | | [SSLNegotiatedKeyExchangeStrength](#SSLNegotiatedKeyExchangeStrength) | Returns the negotiated key exchange algorithm strength. | | [SSLNegotiatedVersion](#SSLNegotiatedVersion) | Returns the negotiated protocol version. | | [SSLSecurityFlags](#SSLSecurityFlags) | Flags that control certificate verification. | | [SSLServerCACerts](#SSLServerCACerts) | A newline separated list of CA certificates to use during SSL server certificate validation. | | [TLS12SignatureAlgorithms](#TLS12SignatureAlgorithms) | Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal. | | [TLS12SupportedGroups](#TLS12SupportedGroups) | The supported groups for ECC. | | [TLS13KeyShareGroups](#TLS13KeyShareGroups) | The groups for which to pregenerate key shares. | | [TLS13SignatureAlgorithms](#TLS13SignatureAlgorithms) | The allowed certificate signature algorithms. | | [TLS13SupportedGroups](#TLS13SupportedGroups) | The supported groups for (EC)DHE key exchange. | | [AbsoluteTimeout](#AbsoluteTimeout) | Determines whether timeouts are inactivity timeouts or absolute timeouts. | | [FirewallData](#FirewallData) | Used to send extra data to the firewall. | | [InBufferSize](#InBufferSize) | The size in bytes of the incoming queue of the socket. | | [OutBufferSize](#OutBufferSize) | The size in bytes of the outgoing queue of the socket. | | [BuildInfo](#BuildInfo) | Information about the product's build. | | [GUIAvailable](#GUIAvailable) | Whether or not a message loop is available for processing events. | | [LicenseInfo](#LicenseInfo) | Information about the current license. | | [MaskSensitiveData](#MaskSensitiveData) | Whether sensitive data is masked in log messages. | | [UseFIPSCompliantAPI](#UseFIPSCompliantAPI) | Tells the component whether or not to use FIPS certified APIs. | | [UseInternalSecurityAPI](#UseInternalSecurityAPI) | Whether or not to use the system security libraries or an internal implementation. | # AllowExtensions Property ([SMTP](#smtp-component) Component) This property is a switch allowing the component to use ESMTP features (Extended SMTP). ## Syntax ```text public bool AllowExtensions { get; set; } ``` ## Default Value True ## Remarks This property is a switch allowing the component to use ESMTP features (Extended SMTP). If this property is True, the component will first send the EHLO greeting (Extended Hello) to the server and, if that fails, the standard HELO command will be sent. This property is True by default but may be disabled if it is known in advance that the [MailServer](#mailserver-property-smtp-component) does not support SMTP extensions. This property is not available at design time. # AuthMechanism Property ([SMTP](#smtp-component) Component) This property is used when connecting to the mail server. ## Syntax ```text public SMTPAuthMechanisms AuthMechanism { get; set; } enum SMTPAuthMechanisms { amUserPassword, amCRAMMD5, amNTLM, amAPOP, amSASLPlain, amSASLDigestMD5, amKerberos, amXOAUTH2 } ``` ## Default Value 0 ## Remarks This is the authentication mechanism property to be used when connecting to the mail server. By default, this property is amUserPassword (0), and if the [User](#user-property-smtp-component) and [Password](#password-property-smtp-component) properties are set, the AUTH command is sent to the server for authentication. If this property is set to amCRAMMD5 (1), CRAM-MD5 authentication is used instead. If this property is set to amNTLM (2), NTLM authentication will be used. If this property is set to amKerberos (6), Kerberos authentication will be used. NOTE: This functionality is available only in Windows. When set to amXOAUTH2 (7), set [User](#user-property-smtp-component) to the username and [AuthorizationIdentity](#AuthorizationIdentity) to the OAuth token. See [AuthorizationIdentity](#AuthorizationIdentity) for details. # BCc Property ([SMTP](#smtp-component) Component) This property includes a comma-separated list of addresses for blind carbon copies (optional). ## Syntax ```text public string BCc { get; set; } ``` ## Default Value "" ## Remarks This property specifies a comma-separated list of destinations for blind carbon copies of the mail message. A copy of the message is sent to each destination. Because no *BCc* SMTP header is created containing the destination addresses, individual recipients never see the list of the other recipients. The component will return an error if the [MailServer](#mailserver-property-smtp-component) returns an error code about any email address specified in [SendTo](#sendto-property-smtp-component) or [Cc](#cc-property-smtp-component) but it will fire an [Error](#error-event-smtp-component) event only if the same thing happens with an email address specified in this property. If the resulting header is longer than [MaxHeaderLength](#MaxHeaderLength), then it is folded according to RFC 822 specifications. NOTE: You must clear the [MessageRecipients](#messagerecipients-property-smtp-component) collection before setting this property to remove previous recipients. # Cc Property ([SMTP](#smtp-component) Component) This property includes a comma-separated list of addresses for carbon copies (optional). ## Syntax ```text public string Cc { get; set; } ``` ## Default Value "" ## Remarks This property specifies a comma-separated list of destinations for carbon copies of the mail message. A copy of the message is sent to each destination, and a *Cc* SMTP header is created containing the destination addresses. This header is sent to every recipient of the message. If you don't want to copy this information to every recipient, then use blind carbon copies instead (see the description of the [BCc](#bcc-property-smtp-component)). The component will return an error if the [MailServer](#mailserver-property-smtp-component) returns an error code about any email address specified in [SendTo](#sendto-property-smtp-component) or Cc but it will fire an [Error](#error-event-smtp-component) event only if the same thing happens with an email address specified in [BCc](#bcc-property-smtp-component). If the resulting header is longer than [MaxHeaderLength](#MaxHeaderLength), then it is folded according to RFC 822 specifications. NOTE: You must clear the [MessageRecipients](#messagerecipients-property-smtp-component) collection before setting this property to remove previous recipients. # Connected Property ([SMTP](#smtp-component) Component) Whether the component is connected. ## Syntax ```text public bool Connected { get; } ``` ## Default Value False ## Remarks This property is used to determine whether or not the component is connected to the remote host. Use the [Connect](#connect-method-smtp-component) and [Disconnect](#disconnect-method-smtp-component) methods to manage the connection. This property is read-only and not available at design time. # DeliveryNotificationTo Property ([SMTP](#smtp-component) Component) This property includes the email address to which to send a delivery notification. ## Syntax ```text public string DeliveryNotificationTo { get; set; } ``` ## Default Value "" ## Remarks This property contains the email address to send to which to send a delivery notification. When set, a Return-Receipt-To header is added to the message. This property should be set to an email address that can receive the delivery notification. # Firewall Property ([SMTP](#smtp-component) Component) A set of properties related to firewall access. ## Syntax ```text public Firewall Firewall { get; set; } ``` ## Remarks This is a [Firewall](#firewall-type)-type property, which contains fields describing the firewall through which the component will attempt to connect. Please refer to the [Firewall](#firewall-type) type for a complete list of fields. # From Property ([SMTP](#smtp-component) Component) This property includes the email address of the sender (required). ## Syntax ```text public string From { get; set; } ``` ## Default Value "" ## Remarks This property is used to create a *From* SMTP header. This header identifies the sender of the message. A valid email address is required. Examples of valid addresses are as follows: *"Friendly Name" * or *address@company.com* If the resulting header is longer than [MaxHeaderLength](#MaxHeaderLength), then it is folded according to RFC 822 specifications. # Idle Property ([SMTP](#smtp-component) Component) The current status of the component. ## Syntax ```text public bool Idle { get; } ``` ## Default Value True ## Remarks This property will be False if the component is currently busy (communicating or waiting for an answer), and True at all other times. This property is read-only. # Importance Property ([SMTP](#smtp-component) Component) This property indicates the importance of the mail message (optional). ## Syntax ```text public SMTPImportances Importance { get; set; } enum SMTPImportances { miUnspecified, miHigh, miNormal, miLow } ``` ## Default Value 0 ## Remarks This property indicates the importance of the mail message (optional). When set, an Importance header will be added to the message. Importance is an indication to the recipient(s) about the level of importance of the message. The possible values are Unspecified (0), High (1), Normal (2), and Low (3). # LastReply Property ([SMTP](#smtp-component) Component) This property indicates the last reply received from the server. ## Syntax ```text public string LastReply { get; } ``` ## Default Value "" ## Remarks This property indicates the last reply received from the server. It can be used for informational purposes. The same information and more also can be retrieved through the [PITrail](#pitrail-event-smtp-component) event. This property is read-only. # LocalHost Property ([SMTP](#smtp-component) Component) The name of the local host or user-assigned IP interface through which connections are initiated or accepted. ## Syntax ```text public string LocalHost { get; set; } ``` ## Default Value "" ## Remarks This property contains the name of the local host as obtained by the *gethostname()* system call, or if the user has assigned an IP address, the value of that address. In multihomed hosts (machines with more than one IP interface) setting LocalHost to the IP address of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. It is recommended to provide an IP address rather than a hostname when setting this property to ensure the desired interface is used. If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface). NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window. # MailPort Property ([SMTP](#smtp-component) Component) This property includes the server port for SMTP (default 25). ## Syntax ```text public int MailPort { get; set; } ``` ## Default Value 25 ## Remarks This property contains the server port for SMTP (default 25). A valid port number (a value between 1 and 65535) is required for the connection to take place. The property must be set before a connection is attempted and cannot be changed once a connection is established. Any attempt to change this property while connected will fail with an error. For an implicit Secure Sockets Layer (SSL), use port 465 (please refer to the [SSLStartMode](#sslstartmode-property-smtp-component) property for more information). This property is not available at design time. # MailServer Property ([SMTP](#smtp-component) Component) This property includes the name or address of a mail server (mail relay). ## Syntax ```text public string MailServer { get; set; } ``` ## Default Value "" ## Remarks This property specifies the IP address (IP number in dotted internet format) or domain name for a mail relay through which messages will be routed. It is set before a connection is attempted and cannot be changed once a connection is in progress. The current version of the component does not provide a default value for the mail relay. You must provide a host name yourself. Generally, any internet host with an SMTP server will suffice (e.g., a UNIX host), but it is preferable to select a MailServer that is close to the machine sending mail. If this property is set to a domain name, a DNS request is initiated. Upon successful termination of the request, this property is set to the corresponding address. If the search is not successful, an error is returned. If the component is configured to use a *SOCKS* firewall, the value assigned to this property may be preceded with an "*". If this is the case, the host name is passed to the firewall unresolved and the firewall performs the DNS resolution. # Message Property ([SMTP](#smtp-component) Component) This property provides a way to set the raw message content. ## Syntax ```text public string Message { get; set; } public byte[] MessageB { get; set; } ``` ## Default Value "" ## Remarks This property may be set instead of [MessageText](#messagetext-property-smtp-component). This value will not be modified in any way by the component and will be sent as is. Use caution when setting this value as all encoding must be done before supplying the value to the component. This property is not available at design time. # MessageDate Property ([SMTP](#smtp-component) Component) This property includes the date of the mail message (optional). ## Syntax ```text public string MessageDate { get; set; } ``` ## Default Value "*" ## Remarks If this property contains a nonempty string, then a *Date* SMTP header is created and attached to the message. If it is an empty string, then the date information is added by the mail relay(s) the message goes through. Special case: If this property is set to the special value "*", a *Date* SMTP header reflecting the current date and time is generated when [MessageHeaders](#messageheaders-property-smtp-component) is computed and the message is sent. This is the default behavior of the component RFC 822 contains detailed date format specifications. An example of a valid date is "Fri, 1 Mar 96 21:24:52 EST". This property is not available at design time. # MessageHeaders Property ([SMTP](#smtp-component) Component) This property includes a collection of RFC 822-encoded headers of the message. ## Syntax ```text public HeaderList MessageHeaders { get; } ``` ## Remarks This property holds the full headers of the message in RFC 822 format. This property is read-only and not available at design time. Please refer to the [Header](#header-type) type for a complete list of fields. # MessageHeadersString Property ([SMTP](#smtp-component) Component) This property includes the string representation of RFC 822-encoded headers of the message. ## Syntax ```text public string MessageHeadersString { get; } ``` ## Default Value "" ## Remarks This property holds the full headers of the message in RFC 822 format. This property is read-only. # MessageId Property ([SMTP](#smtp-component) Component) This property includes the message identifier for the message. ## Syntax ```text public string MessageId { get; set; } ``` ## Default Value "*" ## Remarks This property contains the message identifier for the message. When set, the value of MessageId is used as the Message-Id header value of the message. A special value of "*" will automatically generate a random unique identifier for the message. This property is not available at design time. # MessageRecipients Property ([SMTP](#smtp-component) Component) This property includes the collection of recipients of the message. ## Syntax ```text public MessageRecipientList MessageRecipients { get; } ``` ## Remarks This property contains a collection that describes to whom the message is being sent. You may include all recipients in this property, even Cc's and BCc's, which are specified by the type field. This collection is indexed from *0* to *Count - 1*. Please refer to the [MessageRecipient](#messagerecipient-type) type for a complete list of fields. # MessageText Property ([SMTP](#smtp-component) Component) This property includes the full text of the message to send (without headers). ## Syntax ```text public string MessageText { get; set; } ``` ## Default Value "" ## Remarks This property contains the full text of the message. The text contained in this property should be a collection of lines with lengths less than or equal to 80 bytes separated by CRLF (*"\r\n"*) . The text in the message lines must contain 7-bit characters so that the message can successfully pass through the multitude of mail systems on the Internet. The component automatically escapes lines that start with a "." by adding another as specified in RFC 821. The message text is unescaped by the receiving agent, so the process is fully transparent. # OAuth Property ([SMTP](#smtp-component) Component) The OAuth settings. ## Syntax ```text public MailOAuthSettings OAuth { get; } ``` ## Remarks This property is used to configure the necessary fields to authenticate with the service provider. See the introduction for more information. This property is read-only and not available at design time. Please refer to the [MailOAuthSettings](#mailoauthsettings-type) type for a complete list of fields. # OtherHeaders Property ([SMTP](#smtp-component) Component) This property includes an RFC 822-compliant string consisting of extra headers. ## Syntax ```text public string OtherHeaders { get; set; } ``` ## Default Value "" ## Remarks This property contains a string of headers to be appended to the message headers created from other properties like [SendTo](#sendto-property-smtp-component), [Subject](#subject-property-smtp-component), and so on. The headers must be of the format "header: value" as specified in RFC 822. Header lines should be separated by CRLF (*"\r\n"*) . Use this property with caution. If this property contains invalid headers, message delivery might not be successful. This property is useful for extending the functionality of the component. A good example is delivery of MIME-encoded messages. Special case: If this property starts with an empty line (CRLF), then the value of this property is used instead of the normally computed message headers. **Example. Sending an Email with an Additional Header:** ```text component.MailServer = "MyServer"; component.From = "me@server.com"; component.SendTo = "recipient@server.com"; component.Subject = "My Subject"; component.MessageText = "This is the message body."; component.OtherHeaders = "HeaderName: HeaderValue"; component.Send(); ``` This property is not available at design time. # Password Property ([SMTP](#smtp-component) Component) This property includes a password for logon to the [MailServer](#mailserver-property-smtp-component) . ## Syntax ```text public string Password { get; set; } ``` ## Default Value "" ## Remarks If this property is set to a nonempty string, then when connecting to the [MailServer](#mailserver-property-smtp-component) an AUTH or CRAM-MD5 (depending on the value of [AuthMechanism](#authmechanism-property-smtp-component)) command is sent to provide authentication information for the user. This property is not available at design time. # Priority Property ([SMTP](#smtp-component) Component) This property includes the priority of the mail message (optional). ## Syntax ```text public SMTPPriorities Priority { get; set; } enum SMTPPriorities { epUnspecified, epNormal, epUrgent, epNonUrgent } ``` ## Default Value 0 ## Remarks When this property is set, a priority header will be added to the message. Priority is an indication about the delivery priority of the message. The possible values are epNormal, epUrgent, and epNonUrgent. # ReadReceiptTo Property ([SMTP](#smtp-component) Component) This property includes the email address to send a read-receipt to. ## Syntax ```text public string ReadReceiptTo { get; set; } ``` ## Default Value "" ## Remarks When this property is set, a Disposition-Notification-To header is added to the message. This property should be set to an email address that should receive the read-receipt. # ReplyTo Property ([SMTP](#smtp-component) Component) This property includes a mail address to which to reply (optional). ## Syntax ```text public string ReplyTo { get; set; } ``` ## Default Value "" ## Remarks If this property contains a nonempty string, a *Reply-To* SMTP header is created for the message. This header shows the address to use for replies, which is useful if this address is different from the one in [From](#from-property-smtp-component). If the resulting header is longer than [MaxHeaderLength](#MaxHeaderLength), then it is folded according to RFC 822 specifications. # ReturnPath Property ([SMTP](#smtp-component) Component) This property sets the Return-Path to be used for sending email. ## Syntax ```text public string ReturnPath { get; set; } ``` ## Default Value "" ## Remarks Setting this property sets the Return-Path to be used for sending email. If this is not set, the value in the [From](#from-property-smtp-component) property is used. # SendTo Property ([SMTP](#smtp-component) Component) This property includes a comma-separated list of addresses for destinations (required). ## Syntax ```text public string SendTo { get; set; } ``` ## Default Value "" ## Remarks This property specifies a comma-separated list of destinations for the mail message. A copy of the message is sent to each of them, and a *To* SMTP header is created containing the destination addresses. Examples of valid addresses are as follows: *"Friendly Name" * or *address@company.com* The component will fail if the [MailServer](#mailserver-property-smtp-component) returns an error code about any email address specified in *SendTo* or [Cc](#cc-property-smtp-component) but it will silently ignore the error if the same thing happens with an email address specified in [BCc](#bcc-property-smtp-component). If the resulting header is longer than [MaxHeaderLength](#MaxHeaderLength), then it is folded according to RFC 822 specifications. NOTE: You must clear the [MessageRecipients](#messagerecipients-property-smtp-component) collection before setting this property to remove previous recipients. # Sensitivity Property ([SMTP](#smtp-component) Component) This property indicates the sensitivity of the mail message (optional). ## Syntax ```text public SMTPSensitivities Sensitivity { get; set; } enum SMTPSensitivities { esUnspecified, esPersonal, esPrivate, esCompanyConfidential } ``` ## Default Value 0 ## Remarks This property provides an indication of how sensitive it is to disclose the message to people other than the recipients of the message. When set, a Sensitivity header will added to the message. Possible values are as follows: esPersonal (1), esPrivate (2), and esCompanyConfidential (3). # SSLAcceptServerCert Property ([SMTP](#smtp-component) Component) Instructs the component to unconditionally accept the server certificate that matches the supplied certificate. ## Syntax ```text public Certificate SSLAcceptServerCert { get; set; } ``` ## Remarks If it finds any issues with the certificate presented by the server, the component will normally terminate the connection with an error. You may override this behavior by supplying a value for SSLAcceptServerCert. If the certificate supplied in SSLAcceptServerCert is the same as the certificate presented by the server, then the server certificate is accepted unconditionally, and the connection will continue normally. NOTE: This functionality is provided only for cases in which you otherwise know that you are communicating with the right server. If used improperly, this property may create a security breach. Use it at your own risk. Please refer to the [Certificate](#certificate-type) type for a complete list of fields. # SSLCert Property ([SMTP](#smtp-component) Component) The certificate to be used during Secure Sockets Layer (SSL) negotiation. ## Syntax ```text public Certificate SSLCert { get; set; } ``` ## Remarks This property includes the digital certificate that the component will use during SSL negotiation. Set this property to a valid certificate before starting SSL negotiation. To set a certificate, you may set the [Encoded](#Certificate_f_Encoded) field to the encoded certificate. To select a certificate, use the store and subject fields. Please refer to the [Certificate](#certificate-type) type for a complete list of fields. # SSLEnabled Property ([SMTP](#smtp-component) Component) This property indicates whether Transport Layer Security/Secure Sockets Layer (TLS/SSL) is enabled. ## Syntax ```text public bool SSLEnabled { get; set; } ``` ## Default Value False ## Remarks This property specifies whether TLS/SSL is enabled in the component. When False (default), the component operates in plaintext mode. When True, TLS/SSL is enabled. TLS/SSL may also be enabled by setting [SSLStartMode](#sslstartmode-property-smtp-component). Setting [SSLStartMode](#sslstartmode-property-smtp-component) will automatically update this property value. This property is not available at design time. # SSLProvider Property ([SMTP](#smtp-component) Component) The Secure Sockets Layer/Transport Layer Security (SSL/TLS) implementation to use. ## Syntax ```text public SMTPSSLProviders SSLProvider { get; set; } enum SMTPSSLProviders { sslpAutomatic, sslpPlatform, sslpInternal } ``` ## Default Value 0 ## Remarks This property specifies the SSL/TLS implementation to use. In most cases the default value of *0* (Automatic) is recommended and should not be changed. When set to *0* (Automatic), the component will select whether to use the platform implementation or the internal implementation depending on the operating system as well as the TLS version being used. Possible values are as follows: | | | | --- | --- | | 0 (sslpAutomatic - default) | Automatically selects the appropriate implementation. | | 1 (sslpPlatform) | Uses the platform/system implementation. | | 2 (sslpInternal) | Uses the internal implementation. | **Additional Notes** In most cases using the default value (Automatic) is recommended. The component will select a provider depending on the current platform. When Automatic is selected, on Windows, the component will use the platform implementation. On Linux/macOS, the component will use the internal implementation. When TLS 1.3 is enabled via [SSLEnabledProtocols](#SSLEnabledProtocols), the component will always try and use the platform implementation. If the platform TLS 1.3 implementation is not available, the internal implementation will be used. The .NET Standard library will always use the internal implementation on all platforms. # SSLServerCert Property ([SMTP](#smtp-component) Component) The server certificate for the last established connection. ## Syntax ```text public Certificate SSLServerCert { get; } ``` ## Remarks This property contains the server certificate for the last established connection. SSLServerCert is reset every time a new connection is attempted. This property is read-only. Please refer to the [Certificate](#certificate-type) type for a complete list of fields. # SSLStartMode Property ([SMTP](#smtp-component) Component) This property determines how the component starts the Secure Sockets Layer (SSL) negotiation. ## Syntax ```text public SMTPSSLStartModes SSLStartMode { get; set; } enum SMTPSSLStartModes { sslAutomatic, sslImplicit, sslExplicit, sslNone } ``` ## Default Value 3 ## Remarks The SSLStartMode property may have one of the following values: | | | | --- | --- | | 0 (sslAutomatic) | If the remote port is set to the standard plaintext port of the protocol (where applicable), the component will behave the same as if SSLStartMode is set to sslExplicit. In all other cases, SSL negotiation will be implicit (sslImplicit). | | 1 (sslImplicit) | The SSL negotiation will start immediately after the connection is established. | | 2 (sslExplicit) | The component will first connect in plaintext, and then will explicitly start SSL negotiation through a protocol command such as STARTTLS. | | 3 (sslNone - default) | No SSL negotiation; no SSL security. All communication will be in plaintext mode. | # Subject Property ([SMTP](#smtp-component) Component) This property includes the subject of the mail message (optional). ## Syntax ```text public string Subject { get; set; } ``` ## Default Value "" ## Remarks The string in this property is sent with a *Subject* SMTP header to the mail recipient. If the resulting header is longer than [MaxHeaderLength](#MaxHeaderLength), then it is folded according to RFC 822 specifications. # Timeout Property ([SMTP](#smtp-component) Component) The timeout for the component. ## Syntax ```text public int Timeout { get; set; } ``` ## Default Value 60 ## Remarks If the Timeout property is set to 0, all operations will run uninterrupted until successful completion or an error condition is encountered. If Timeout is set to a positive value, the component will wait for the operation to complete before returning control. The component will use [DoEvents](#doevents-method-smtp-component) to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive. If Timeout expires, and the operation is not yet complete, the component throws an exception. NOTE: By default, all timeouts are *inactivity timeouts*, that is, the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received. The default value for the Timeout property is 60 seconds. # User Property ([SMTP](#smtp-component) Component) This property includes the user identifier needed to log in as in the [MailServer](#mailserver-property-smtp-component) . ## Syntax ```text public string User { get; set; } ``` ## Default Value "" ## Remarks If this property is set to a nonempty string, then when connecting to the [MailServer](#mailserver-property-smtp-component) an *AUTH* or *CRAM-MD5* (depending on the value of [AuthMechanism](#authmechanism-property-smtp-component)) command is sent to provide authentication information for the user. This property is not available at design time. # Config Method ([SMTP](#smtp-component) Component) Sets or retrieves a configuration setting. ## Syntax ```text public string Config(string configurationString); Async Version public async Task Config(string configurationString); public async Task Config(string configurationString, CancellationToken cancellationToken); ``` ## Remarks Config is a generic method available in every component. It is used to set and retrieve [configuration settings](#config-settings-smtp-component) for the component. These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these *internal properties* is provided through the Config method. To set a configuration setting named *PROPERTY*, you must call *Config("PROPERTY=VALUE")*, where *VALUE* is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter). To read (query) the value of a [configuration setting](#config-settings-smtp-component), you must call *Config("PROPERTY")*. The value will be returned as a string. # Connect Method ([SMTP](#smtp-component) Component) This method connects to the mail relay and sends the SMTP * HELO * command. ## Syntax ```text public void Connect(); Async Version public async Task Connect(); public async Task Connect(CancellationToken cancellationToken); ``` ## Remarks This method connects to the mail relay and sends the SMTP *HELO* command, thus preparing to send messages. Any number of messages can later be sent using the [Send](#send-method-smtp-component) method. **Example. Connecting and Sending an Email:** ```text control.MailServer = "MyServer" control.From = "me@server.com" control.SendTo = "recipient@server.com" control.Subject = "My Subject" control.MessageText = "This is the message body" control.Connect() control.Send() control.Disconnect() ``` # Disconnect Method ([SMTP](#smtp-component) Component) This method disconnects from the SMTP server. ## Syntax ```text public void Disconnect(); Async Version public async Task Disconnect(); public async Task Disconnect(CancellationToken cancellationToken); ``` ## Remarks This method disconnects from the mail relay. # DoEvents Method ([SMTP](#smtp-component) Component) This method processes events from the internal message queue. ## Syntax ```text public void DoEvents(); Async Version public async Task DoEvents(); public async Task DoEvents(CancellationToken cancellationToken); ``` ## Remarks When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns. # Expand Method ([SMTP](#smtp-component) Component) This method asks the [MailServer](#mailserver-property-smtp-component) to expand a name or mailing list. ## Syntax ```text public void Expand(string emailAddress); Async Version public async Task Expand(string emailAddress); public async Task Expand(string emailAddress, CancellationToken cancellationToken); ``` ## Remarks This method asks the [MailServer](#mailserver-property-smtp-component) to expand a name or mailing list. The resulting response is provided in one or more [Expand](#expand-event-smtp-component) events (one for each address). The component will try to connect to the mail relay if it is not already connected. # Interrupt Method ([SMTP](#smtp-component) Component) This method interrupts the current method. ## Syntax ```text public void Interrupt(); Async Version public async Task Interrupt(); public async Task Interrupt(CancellationToken cancellationToken); ``` ## Remarks If there is no method in progress, Interrupt simply returns, doing nothing. # ProcessQueue Method ([SMTP](#smtp-component) Component) This method sends the messages that previously have been queued into * QueueDir * . ## Syntax ```text public void ProcessQueue(string queueDir); Async Version public async Task ProcessQueue(string queueDir); public async Task ProcessQueue(string queueDir, CancellationToken cancellationToken); ``` ## Remarks This method sends the messages that previously have been queued into *QueueDir*. The [PITrail](#pitrail-event-smtp-component) event shows the interaction with the server as messages are processed. This method looks in the directory for files with the extension ".queued" and starts processing them. When processing starts, the file extension is changed to ".sending". If an error happens at this stage, the sending process is aborted, and the file extension is changed to ".failed". If the file is successfully sent, the file is normally deleted, unless the [KeepQueue](#KeepQueue) configuration setting is set to True, in which case the file extension is instead changed to ".sent" and the queue file is not deleted. # Queue Method ([SMTP](#smtp-component) Component) This method queues the message into * QueueDir * . ## Syntax ```text public string Queue(string queueDir); Async Version public async Task Queue(string queueDir); public async Task Queue(string queueDir, CancellationToken cancellationToken); ``` ## Remarks This method queues the message into *QueueDir*. The message is queued into a unique file into the directory *QueueDir* for future processing. *QueueDir* must already exist, or an error will be generated. Alternatively, *QueueDir* may be set to "*" to return the result as a string instead of writing it to a file. This method returns the name of the unique queue file created in *QueueDir*. The file extension is ".queued". Please refer to the [ProcessQueue](#processqueue-method-smtp-component) method for more information on email queue processing. # Reset Method ([SMTP](#smtp-component) Component) This method will reset the component. ## Syntax ```text public void Reset(); Async Version public async Task Reset(); public async Task Reset(CancellationToken cancellationToken); ``` ## Remarks This method will reset the component's properties to their default values. # ResetHeaders Method ([SMTP](#smtp-component) Component) This method resets all the message headers to empty. ## Syntax ```text public void ResetHeaders(); Async Version public async Task ResetHeaders(); public async Task ResetHeaders(CancellationToken cancellationToken); ``` ## Remarks This method resets all the message headers to "" (empty string). Use this method before creating a new message, so that headers from the previous message are not carried over to the next one. # Send Method ([SMTP](#smtp-component) Component) This method sends the current message. ## Syntax ```text public void Send(); Async Version public async Task Send(); public async Task Send(CancellationToken cancellationToken); ``` ## Remarks This method sends the current message. If the component is not connected to the mail relay, a connection is created, the message is sent, and then the connection is closed unless an error occurs. If the component is already connected (by use of the [Connect](#connect-method-smtp-component) method), the connection will remain open after the message is sent. To disconnect, call the [Disconnect](#disconnect-method-smtp-component) method. **Example. Send an Email:** ```text SMTPControl.MailServer = "MyServer" SMTPControl.From = "me@server.com" SMTPControl.SendTo = "recipient@server.com" SMTPControl.Subject = "My Subject" SMTPControl.MessageText = "This is the message body" SMTPControl.Send() ``` # SendCommand Method ([SMTP](#smtp-component) Component) This method sends the exact command directly to the server. ## Syntax ```text public void SendCommand(string command); Async Version public async Task SendCommand(string command); public async Task SendCommand(string command, CancellationToken cancellationToken); ``` ## Remarks This method sends the command specified by *Command* to the server exactly as it is provided. Use this method to send additional or custom commands directly to the server. After calling this method, check the [LastReply](#lastreply-property-smtp-component) property or monitor the [PITrail](#pitrail-event-smtp-component) event to obtain the server's response. # SendToTerminalAndEmail Method ([SMTP](#smtp-component) Component) This method sends to terminal and email. ## Syntax ```text public void SendToTerminalAndEmail(); Async Version public async Task SendToTerminalAndEmail(); public async Task SendToTerminalAndEmail(CancellationToken cancellationToken); ``` ## Remarks This method is similar to [Send](#send-method-smtp-component) but requests also that the message is sent to the terminal of the users as well, if they are logged on and accept terminal messages. This method requires that [AllowExtensions](#allowextensions-property-smtp-component) is set to True and is not supported by all mail relays. # SendToTerminalOnly Method ([SMTP](#smtp-component) Component) This method sends to terminal only. ## Syntax ```text public void SendToTerminalOnly(); Async Version public async Task SendToTerminalOnly(); public async Task SendToTerminalOnly(CancellationToken cancellationToken); ``` ## Remarks This method is similar to *Send* but requests instead that the message is sent to the user's terminal. An exception with the server's response is raised if the user is not logged in or does not accept terminal messages. This method requires that [AllowExtensions](#allowextensions-property-smtp-component) is set to True and is not supported by all mail relays. # SendToTerminalOrEmail Method ([SMTP](#smtp-component) Component) This method sends to terminal or email. ## Syntax ```text public void SendToTerminalOrEmail(); Async Version public async Task SendToTerminalOrEmail(); public async Task SendToTerminalOrEmail(CancellationToken cancellationToken); ``` ## Remarks This method is similar to [Send](#send-method-smtp-component) but requests instead that the message is first sent to the user's terminal. If the user is not logged in or does not accept terminal messages, the message is sent to his or her mailbox. This method requires that [AllowExtensions](#allowextensions-property-smtp-component) is set to True and is not supported by all mail relays. # SetMessageStream Method ([SMTP](#smtp-component) Component) This method sets the stream to be uploaded to the server as part of the message. ## Syntax ```text public void SetMessageStream(System.IO.Stream messageStream); Async Version public async Task SetMessageStream(System.IO.Stream messageStream); public async Task SetMessageStream(System.IO.Stream messageStream, CancellationToken cancellationToken); ``` ## Remarks This method sets the stream to be uploaded to the server as part of the message. If an upload stream is set before the [Send](#send-method-smtp-component) method is called, the content of the stream will be read by the component and uploaded to the server. The stream should be open and normally set to position *0*. The component will automatically close this stream if [CloseStreamAfterTransfer](#CloseStreamAfterTransfer) is set to True (default). If the stream is closed, you will need to call this method again before calling [Send](#send-method-smtp-component) again. The content of the stream will be read from the current position all the way to the end. NOTE: This method and LocalFile will reset the other. # Verify Method ([SMTP](#smtp-component) Component) This method sends a verification request to the SMTP server. ## Syntax ```text public void Verify(string emailAddress); Async Version public async Task Verify(string emailAddress); public async Task Verify(string emailAddress, CancellationToken cancellationToken); ``` ## Remarks This method asks the [MailServer](#mailserver-property-smtp-component) to verify the email address provided in the *'EmailAddress'* parameter. # ConnectionStatus Event ([SMTP](#smtp-component) Component) Fired to indicate changes in the connection state. ## Syntax ```text public event OnConnectionStatusHandler OnConnectionStatus; public delegate void OnConnectionStatusHandler(object sender, SMTPConnectionStatusEventArgs e); public class SMTPConnectionStatusEventArgs : EventArgs { public string ConnectionEvent { get; } public int StatusCode { get; } public string Description { get; } } ``` ## Remarks This event is fired when the connection state changes: for example, completion of a firewall or proxy connection or completion of a security handshake. The *ConnectionEvent* parameter indicates the type of connection event. Values may include the following: | | | | --- | --- | | | Firewall connection complete. | | | Secure Sockets Layer (SSL) or S/Shell handshake complete (where applicable). | | | Remote host connection complete. | | | Remote host disconnected. | | | SSL or S/Shell connection broken. | | | Firewall host disconnected. | *StatusCode* has the error code returned by the Transmission Control Protocol (TCP)/IP stack. *Description* contains a description of this code. The value of *StatusCode* is equal to the value of the error. # EndTransfer Event ([SMTP](#smtp-component) Component) This event is fired when the message text completes transferring. ## Syntax ```text public event OnEndTransferHandler OnEndTransfer; public delegate void OnEndTransferHandler(object sender, SMTPEndTransferEventArgs e); public class SMTPEndTransferEventArgs : EventArgs { public int Direction { get; } } ``` ## Remarks If [MessageText](#messagetext-property-smtp-component) is not empty, the EndTransfer event is fired when the [MessageText](#messagetext-property-smtp-component) finishes transferring from the local host to the [MailServer](#mailserver-property-smtp-component). If [MessageText](#messagetext-property-smtp-component) is empty, the event is not fired. If a file is attached to the [MessageText](#messagetext-property-smtp-component) via the AttachedFile property, then EndTransfer fires again when the file finishes transferring. For more information, go to the description of the AttachedFile property. The *Direction* parameter shows whether the client (0) or the server (1) is sending the data. # Error Event ([SMTP](#smtp-component) Component) Fired when information is available about errors during data delivery. ## Syntax ```text public event OnErrorHandler OnError; public delegate void OnErrorHandler(object sender, SMTPErrorEventArgs e); public class SMTPErrorEventArgs : EventArgs { public int ErrorCode { get; } public string Description { get; } } ``` ## Remarks The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception. The *ErrorCode* parameter contains an error code, and the *Description* parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the [Error Codes](#trappable-errors-smtp-component) section. # Expand Event ([SMTP](#smtp-component) Component) This event is fired for every email address returned by the server when the [Expand](#expand-method-smtp-component) method is called. ## Syntax ```text public event OnExpandHandler OnExpand; public delegate void OnExpandHandler(object sender, SMTPExpandEventArgs e); public class SMTPExpandEventArgs : EventArgs { public string Address { get; } } ``` ## Remarks This event is fired for every email address as returned by the mail server when the [Expand](#expand-method-smtp-component) method is called. The *Address* parameter may contain a name and an email address, or just an email address, suitable for any of the addressing properties. # LaunchBrowser Event ([SMTP](#smtp-component) Component) Fires before launching a browser with the authorization URL. ## Syntax ```text public event OnLaunchBrowserHandler OnLaunchBrowser; public delegate void OnLaunchBrowserHandler(object sender, SMTPLaunchBrowserEventArgs e); public class SMTPLaunchBrowserEventArgs : EventArgs { public string URL { get; set; } public string Command { get; set; } } ``` ## Remarks When the ClientProfile property is set to ocpApplication and GetAuthorization is called, the component will fire this event with the *Command*, which will be executed by the component. The *URL* parameter will be the authorization URL that the user will be directed to authenticate. Within this event, you may override the current value of either *Command* or *URL* and provide your own value. If *Command* is set to an empty string, the component will not attempt to launch the browser and instead you will be responsible for directing the user to the authorization URL specified by the URL parameter. If *Command* is not empty, the URL will be appended to the end. # Log Event ([SMTP](#smtp-component) Component) Fired once for each log message. ## Syntax ```text public event OnLogHandler OnLog; public delegate void OnLogHandler(object sender, SMTPLogEventArgs e); public class SMTPLogEventArgs : EventArgs { public int LogLevel { get; } public string Message { get; } public string LogType { get; } } ``` ## Remarks This event is fired once for each log message generated by the component. The verbosity is controlled by the [LogLevel](#LogLevel) setting. *LogLevel* indicates the level of message. Possible values are as follows: | | | | --- | --- | | 0 (None) | No events are logged. | | 1 (Info - default) | Informational events are logged. | | 2 (Verbose) | Detailed data are logged. | | 3 (Debug) | Debug data are logged. | The value 1 (Info) logs basic information, including the URL, HTTP version, and status details. The value 2 (Verbose) logs additional information about the request and response. The value 3 (Debug) logs the headers and body for both the request and response, as well as additional debug information (if any). *Message* is the log entry. *LogType* identifies the type of log entry. Possible values are as follows: - "Info" - "RequestHeaders" - "ResponseHeaders" - "RequestBody" - "ResponseBody" - "ProxyRequest" - "ProxyResponse" - "FirewallRequest" - "FirewallResponse" # PITrail Event ([SMTP](#smtp-component) Component) This event traces the commands sent to the mail server, and the respective replies. ## Syntax ```text public event OnPITrailHandler OnPITrail; public delegate void OnPITrailHandler(object sender, SMTPPITrailEventArgs e); public class SMTPPITrailEventArgs : EventArgs { public int Direction { get; } public string Message { get; } } ``` ## Remarks The PITrail event is useful for debugging purposes. It shows all of the interaction between the client and the server, line by line, except for message header and body transfers. The *Message* parameter contains the full text of the message. The *Direction* parameter shows the originator of the message: | | | | --- | --- | | 0 (Client) | The Message originates from the client. | | 1 (Server) | The Message originates from the server. | | 2 (Info) | The Message is an informative message originating from the client software (the component code). | # SSLServerAuthentication Event ([SMTP](#smtp-component) Component) Fired after the server presents its certificate to the client. ## Syntax ```text public event OnSSLServerAuthenticationHandler OnSSLServerAuthentication; public delegate void OnSSLServerAuthenticationHandler(object sender, SMTPSSLServerAuthenticationEventArgs e); public class SMTPSSLServerAuthenticationEventArgs : EventArgs { public string CertEncoded { get; } public byte[] CertEncodedB { get; } public string CertSubject { get; } public string CertIssuer { get; } public string Status { get; } public bool Accept { get; set; } } ``` ## Remarks During this event, the client can decide whether or not to continue with the connection process. The *Accept* parameter is a recommendation on whether to continue or close the connection. This is just a suggestion: application software must use its own logic to determine whether or not to continue. When *Accept* is False, *Status* shows why the verification failed (otherwise, *Status* contains the string *OK*). If it is decided to continue, you can override and accept the certificate by setting the *Accept* parameter to True. # SSLStatus Event ([SMTP](#smtp-component) Component) Fired when secure connection progress messages are available. ## Syntax ```text public event OnSSLStatusHandler OnSSLStatus; public delegate void OnSSLStatusHandler(object sender, SMTPSSLStatusEventArgs e); public class SMTPSSLStatusEventArgs : EventArgs { public string Message { get; } } ``` ## Remarks The event is fired for informational and logging purposes only. This event tracks the progress of the connection. # StartTransfer Event ([SMTP](#smtp-component) Component) This event is fired when the message text starts transferring. ## Syntax ```text public event OnStartTransferHandler OnStartTransfer; public delegate void OnStartTransferHandler(object sender, SMTPStartTransferEventArgs e); public class SMTPStartTransferEventArgs : EventArgs { public int Direction { get; } } ``` ## Remarks If [MessageText](#messagetext-property-smtp-component) is not empty, the StartTransfer event is fired when the [MessageText](#messagetext-property-smtp-component) starts transferring from the local host to the [MailServer](#mailserver-property-smtp-component). If [MessageText](#messagetext-property-smtp-component) is empty, the event is not fired. If a file is attached to the [MessageText](#messagetext-property-smtp-component) via the AttachedFile property, then StartTransfer fires again when the file starts transferring. Please go to the description of the AttachedFile property for more information. The *Direction* parameter shows whether the client (0) or the server (1) is sending the data. # Transfer Event ([SMTP](#smtp-component) Component) This event is fired when the message text is transferred to [MailServer](#mailserver-property-smtp-component) . ## Syntax ```text public event OnTransferHandler OnTransfer; public delegate void OnTransferHandler(object sender, SMTPTransferEventArgs e); public class SMTPTransferEventArgs : EventArgs { public int Direction { get; } public long BytesTransferred { get; } public int PercentDone { get; } public string Text { get; } public byte[] TextB { get; } } ``` ## Remarks One or more Transfer events are fired during message delivery. Messages consist of [MessageText](#messagetext-property-smtp-component) and an optional AttachedFile. The *BytesTransferred* parameter shows the number of bytes sent starting from the beginning of [MessageText](#messagetext-property-smtp-component) or AttachedFile. *Text* contains the current portion of the message being sent. The *Direction* parameter shows whether the client (0) or the server (1) is sending the data. The *PercentDone* parameter shows the progress of the transfer in the corresponding direction. If *PercentDone* can not be calculated the value will be -1. NOTE: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance. # Certificate Type This is the digital certificate being used. ## Remarks This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates. The following fields are available: - [EffectiveDate](#Certificate_f_EffectiveDate) - [ExpirationDate](#Certificate_f_ExpirationDate) - [ExtendedKeyUsage](#Certificate_f_ExtendedKeyUsage) - [Fingerprint](#Certificate_f_Fingerprint) - [FingerprintSHA1](#Certificate_f_FingerprintSHA1) - [FingerprintSHA256](#Certificate_f_FingerprintSHA256) - [Issuer](#Certificate_f_Issuer) - [PrivateKey](#Certificate_f_PrivateKey) - [PrivateKeyAvailable](#Certificate_f_PrivateKeyAvailable) - [PrivateKeyContainer](#Certificate_f_PrivateKeyContainer) - [PublicKey](#Certificate_f_PublicKey) - [PublicKeyAlgorithm](#Certificate_f_PublicKeyAlgorithm) - [PublicKeyLength](#Certificate_f_PublicKeyLength) - [SerialNumber](#Certificate_f_SerialNumber) - [SignatureAlgorithm](#Certificate_f_SignatureAlgorithm) - [Store](#Certificate_f_Store) - [StorePassword](#Certificate_f_StorePassword) - [StoreType](#Certificate_f_StoreType) - [SubjectAltNames](#Certificate_f_SubjectAltNames) - [ThumbprintMD5](#Certificate_f_ThumbprintMD5) - [ThumbprintSHA1](#Certificate_f_ThumbprintSHA1) - [ThumbprintSHA256](#Certificate_f_ThumbprintSHA256) - [Usage](#Certificate_f_Usage) - [UsageFlags](#Certificate_f_UsageFlags) - [Version](#Certificate_f_Version) - [Subject](#Certificate_f_Subject) - [Encoded](#Certificate_f_Encoded) ## Fields **EffectiveDate** *string (read-only)* Default: "" The date on which this certificate becomes valid. Before this date, it is not valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date: 23-Jan-2000 15:00:00. **ExpirationDate** *string (read-only)* Default: "" The date on which the certificate expires. After this date, the certificate will no longer be valid. The date is localized to the system's time zone. The following example illustrates the format of an encoded date: 23-Jan-2001 15:00:00. **ExtendedKeyUsage** *string (read-only)* Default: "" A comma-delimited list of extended key usage identifiers. These are the same as ASN.1 object identifiers (OIDs). **Fingerprint** *string (read-only)* Default: "" The hex-encoded, 16-byte MD5 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys. The following example illustrates the format: *bc:2a:72:af:fe:58:17:43:7a:5f:ba:5a:7c:90:f7:02* **FingerprintSHA1** *string (read-only)* Default: "" The hex-encoded, 20-byte SHA-1 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys. The following example illustrates the format: *30:7b:fa:38:65:83:ff:da:b4:4e:07:3f:17:b8:a4:ed:80:be:ff:84* **FingerprintSHA256** *string (read-only)* Default: "" The hex-encoded, 32-byte SHA-256 fingerprint of the certificate. This property is primarily used for keys which do not have a corresponding X.509 public certificate, such as PEM keys that only contain a private key. It is commonly used for SSH keys. The following example illustrates the format: *6a:80:5c:33:a9:43:ea:b0:96:12:8a:64:96:30:ef:4a:8a:96:86:ce:f4:c7:be:10:24:8e:2b:60:9e:f3:59:53* **Issuer** *string (read-only)* Default: "" The issuer of the certificate. This field contains a string representation of the name of the issuing authority for the certificate. **PrivateKey** *string (read-only)* Default: "" The private key of the certificate (if available). The key is provided as PEM/Base64-encoded data. NOTE: The [PrivateKey](#Certificate_f_PrivateKey) may be available but not exportable. In this case, [PrivateKey](#Certificate_f_PrivateKey) returns an empty string. **PrivateKeyAvailable** *bool (read-only)* Default: False Whether a [PrivateKey](#Certificate_f_PrivateKey) is available for the selected certificate. If [PrivateKeyAvailable](#Certificate_f_PrivateKeyAvailable) is True, the certificate may be used for authentication purposes (e.g., server authentication). **PrivateKeyContainer** *string (read-only)* Default: "" The name of the [PrivateKey](#Certificate_f_PrivateKey) container for the certificate (if available). This functionality is available only on Windows platforms. **PublicKey** *string (read-only)* Default: "" The public key of the certificate. The key is provided as PEM/Base64-encoded data. **PublicKeyAlgorithm** *string (read-only)* Default: "" The textual description of the certificate's public key algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_DH") or an object identifier (OID) string representing the algorithm. **PublicKeyLength** *int (read-only)* Default: 0 The length of the certificate's public key (in bits). Common values are 512, 1024, and 2048. **SerialNumber** *string (read-only)* Default: "" The serial number of the certificate encoded as a string. The number is encoded as a series of hexadecimal digits, with each pair representing a byte of the serial number. **SignatureAlgorithm** *string (read-only)* Default: "" The text description of the certificate's signature algorithm. The property contains either the name of the algorithm (e.g., "RSA" or "RSA_MD5RSA") or an object identifier (OID) string representing the algorithm. **Store** *string* Default: "MY" The name of the certificate store for the client certificate. The [StoreType](#Certificate_f_StoreType) field denotes the type of the certificate store specified by [Store](#Certificate_f_Store). If the store is password-protected, specify the password in [StorePassword](#Certificate_f_StorePassword). [Store](#Certificate_f_Store) is used in conjunction with the [Subject](#Certificate_f_Subject) field to specify client certificates. If [Store](#Certificate_f_Store) has a value, and [Subject](#Certificate_f_Subject) or [Encoded](#Certificate_f_Encoded) is set, a search for a certificate is initiated. Please see the [Subject](#Certificate_f_Subject) field for details. Designations of certificate stores are platform dependent. The following designations are the most common User and Machine certificate stores in Windows: | | | | --- | --- | | MY | A certificate store holding personal certificates with their associated private keys. | | CA | Certifying authority certificates. | | ROOT | Root certificates. | When the certificate store type is *cstPFXFile*, this property must be set to the name of the file. When the type is *cstPFXBlob*, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store). **StoreB** *byte []* Default: "MY" The name of the certificate store for the client certificate. The [StoreType](#Certificate_f_StoreType) field denotes the type of the certificate store specified by [Store](#Certificate_f_Store). If the store is password-protected, specify the password in [StorePassword](#Certificate_f_StorePassword). [Store](#Certificate_f_Store) is used in conjunction with the [Subject](#Certificate_f_Subject) field to specify client certificates. If [Store](#Certificate_f_Store) has a value, and [Subject](#Certificate_f_Subject) or [Encoded](#Certificate_f_Encoded) is set, a search for a certificate is initiated. Please see the [Subject](#Certificate_f_Subject) field for details. Designations of certificate stores are platform dependent. The following designations are the most common User and Machine certificate stores in Windows: | | | | --- | --- | | MY | A certificate store holding personal certificates with their associated private keys. | | CA | Certifying authority certificates. | | ROOT | Root certificates. | When the certificate store type is *cstPFXFile*, this property must be set to the name of the file. When the type is *cstPFXBlob*, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store). **StorePassword** *string* Default: "" If the type of certificate store requires a password, this field is used to specify the password needed to open the certificate store. **StoreType** *CertStoreTypes* Default: 0 The type of certificate store for this certificate. The component supports both public and private keys in a variety of formats. When the *cstAuto* value is used, the component will automatically determine the type. This field can take one of the following values: ```csharp sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll", "123456", // PIN "CN=cert_subject"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22); ``` ```csharp certmgr.CertStoreType = CertStoreTypes.cstPKCS11; certmgr.OnCertList += (s, e) => { secKeyBlob = e.CertEncoded; }; certmgr.CertStore = @"C:\Program Files\OpenSC Project\OpenSC\pkcs11\opensc-pkcs11.dll"; certmgr.CertStorePassword = "123456"; // PIN certmgr.ListStoreCertificates(); sftp.SSHCert = new Certificate(CertStoreTypes.cstPKCS11, secKeyBlob, "123456", "*"); sftp.SSHUser = "test"; sftp.SSHLogon("myhost", 22); ``` | | | | --- | --- | | 0 (cstUser - default) | For Windows, this specifies that the certificate store is a certificate store owned by the current user. NOTE: This store type is not available in Java. | | 1 (cstMachine) | For Windows, this specifies that the certificate store is a machine store. NOTE: This store type is not available in Java. | | 2 (cstPFXFile) | The certificate store is the name of a PFX (PKCS#12) file containing certificates. | | 3 (cstPFXBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in PFX (PKCS#12) format. | | 4 (cstJKSFile) | The certificate store is the name of a Java Key Store (JKS) file containing certificates. NOTE: This store type is only available in Java. | | 5 (cstJKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in Java Key Store (JKS) format. NOTE: This store type is only available in Java. | | 6 (cstPEMKeyFile) | The certificate store is the name of a PEM-encoded file that contains a private key and an optional certificate. | | 7 (cstPEMKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a private key and an optional certificate. | | 8 (cstPublicKeyFile) | The certificate store is the name of a file that contains a PEM- or DER-encoded public key certificate. | | 9 (cstPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains a PEM- or DER-encoded public key certificate. | | 10 (cstSSHPublicKeyBlob) | The certificate store is a string (binary or Base64-encoded) that contains an SSH-style public key. | | 11 (cstP7BFile) | The certificate store is the name of a PKCS#7 file containing certificates. | | 12 (cstP7BBlob) | The certificate store is a string (binary) representing a certificate store in PKCS#7 format. | | 13 (cstSSHPublicKeyFile) | The certificate store is the name of a file that contains an SSH-style public key. | | 14 (cstPPKFile) | The certificate store is the name of a file that contains a PPK (PuTTY Private Key). | | 15 (cstPPKBlob) | The certificate store is a string (binary) that contains a PPK (PuTTY Private Key). | | 16 (cstXMLFile) | The certificate store is the name of a file that contains a certificate in XML format. | | 17 (cstXMLBlob) | The certificate store is a string that contains a certificate in XML format. | | 18 (cstJWKFile) | The certificate store is the name of a file that contains a JWK (JSON Web Key). | | 19 (cstJWKBlob) | The certificate store is a string that contains a JWK (JSON Web Key). | | 21 (cstBCFKSFile) | The certificate store is the name of a file that contains a BCFKS (Bouncy Castle FIPS Key Store). NOTE: This store type is only available in Java and .NET. | | 22 (cstBCFKSBlob) | The certificate store is a string (binary or Base64-encoded) representing a certificate store in BCFKS (Bouncy Castle FIPS Key Store) format. NOTE: This store type is only available in Java and .NET. | | 23 (cstPKCS11) | The certificate is present on a physical security key accessible via a PKCS#11 interface. To use a security key, create a new [Certificate](#certificate-type) object and pass cstPKCS11 as the [StoreType](#Certificate_f_StoreType), the full path of the PKCS#11 DLL as the [Store](#Certificate_f_Store), and the PIN as the [StorePassword](#Certificate_f_StorePassword). Code Example. SSH Authentication with Security Key (without CertMgr): Alternatively, collect the necessary data using the [CertMgr](CertMgr.md#CertMgr) component by calling the [ListStoreCertificates](CertMgr.md#CertMgr_m_ListStoreCertificates) method after setting the corresponding properties accordingly. The certificate information returned in the [CertList](CertMgr.md#CertMgr_e_CertList) event's CertEncoded parameter may be saved for later use. When using a certificate obtained with this approach, pass the previously saved security key information as the [Store](#Certificate_f_Store) and set [StorePassword](#Certificate_f_StorePassword) to the PIN. Code Example. SSH Authentication with Security Key (with CertMgr): | | 99 (cstAuto) | The store type is automatically detected from the input data. This setting may be used with both public and private keys and can detect any of the supported formats automatically. | **SubjectAltNames** *string (read-only)* Default: "" Comma-separated lists of alternative subject names for the certificate. **ThumbprintMD5** *string (read-only)* Default: "" The MD5 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed. **ThumbprintSHA1** *string (read-only)* Default: "" The SHA-1 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed. **ThumbprintSHA256** *string (read-only)* Default: "" The SHA-256 hash of the certificate. It is primarily used for X.509 certificates. If the hash does not already exist, it is automatically computed. **Usage** *string (read-only)* Default: "" The text description of [UsageFlags](#Certificate_f_UsageFlags). This value will be one or more of the following strings and will be separated by commas: - Digital Signature - Non-Repudiation - Key Encipherment - Data Encipherment - Key Agreement - Certificate Signing - CRL Signing - Encipher Only If the provider is OpenSSL, the value is a comma-separated list of X.509 certificate extension names. **UsageFlags** *int (read-only)* Default: 0 The flags that show intended use for the certificate. The value of [UsageFlags](#Certificate_f_UsageFlags) is a combination of the following flags: | | | | --- | --- | | 0x80 | Digital Signature | | 0x40 | Non-Repudiation | | 0x20 | Key Encipherment | | 0x10 | Data Encipherment | | 0x08 | Key Agreement | | 0x04 | Certificate Signing | | 0x02 | CRL Signing | | 0x01 | Encipher Only | Please see the [Usage](#Certificate_f_Usage) field for a text representation of [UsageFlags](#Certificate_f_UsageFlags). This functionality currently is not available when the provider is OpenSSL. **Version** *string (read-only)* Default: "" The certificate's version number. The possible values are the strings "V1", "V2", and "V3". **Subject** *string* Default: "" The subject of the certificate used for client authentication. This field will be populated with the full subject of the loaded certificate. When loading a certificate, the subject is used to locate the certificate in the store. If an exact match is not found, the store is searched for subjects containing the value of the property. If a match is still not found, the property is set to an empty string, and no certificate is selected. The special value "*" picks a random certificate in the certificate store. The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=example@email.com". Common fields and their meanings are as follows: | Field | Meaning | | --- | --- | | CN | Common Name. This is commonly a hostname like www.server.com. | | O | Organization | | OU | Organizational Unit | | L | Locality | | S | State | | C | Country | | E | Email Address | If a field value contains a comma, it must be quoted. **Encoded** *string* Default: "" The certificate (PEM/Base64 encoded). This field is used to assign a specific certificate. The [Store](#Certificate_f_Store) and [Subject](#Certificate_f_Subject) fields also may be used to specify a certificate. When [Encoded](#Certificate_f_Encoded) is set, a search is initiated in the current [Store](#Certificate_f_Store) for the private key of the certificate. If the key is found, [Subject](#Certificate_f_Subject) is updated to reflect the full subject of the selected certificate; otherwise, [Subject](#Certificate_f_Subject) is set to an empty string. **EncodedB** *byte []* Default: "" The certificate (PEM/Base64 encoded). This field is used to assign a specific certificate. The [Store](#Certificate_f_Store) and [Subject](#Certificate_f_Subject) fields also may be used to specify a certificate. When [Encoded](#Certificate_f_Encoded) is set, a search is initiated in the current [Store](#Certificate_f_Store) for the private key of the certificate. If the key is found, [Subject](#Certificate_f_Subject) is updated to reflect the full subject of the selected certificate; otherwise, [Subject](#Certificate_f_Subject) is set to an empty string. ## Constructors ```text public Certificate(); ``` Creates a instance whose properties can be set. ```text public Certificate(string certificateFile); ``` Opens * CertificateFile * and reads out the contents as an X.509 public key. ```text public Certificate(byte[] encoded); ``` Parses * Encoded * as an X.509 public key. ```text public Certificate(CertStoreTypes storeType, string store, string storePassword, string subject); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a file containing the certificate store. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, string store, string storePassword, string subject, string configurationString); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a file containing the certificate store. * StorePassword * is the password used to protect the store. * ConfigurationString * is a newline-separated list of name-value pairs that may be used to modify the default behavior. Possible values include "PersistPFXKey", which shows whether or not the PFX key is persisted after performing operations with the private key. This correlates to the PKCS12_NO_PERSIST_KEY CryptoAPI option. The default value is True (the key is persisted). "Thumbprint" - an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to the * cstUser * , * cstMachine * , * cstPublicKeyFile * , and * cstPFXFile * store types. "UseInternalSecurityAPI" shows whether the platform (default) or the internal security API is used when performing certificate-related operations. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, string store, string storePassword, byte[] encoded); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a file containing the certificate store. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will load * Encoded * as an X.509 certificate and search the opened store for a corresponding private key. ```text public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, string subject); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a byte array containing the certificate data. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, string subject, string configurationString); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a byte array containing the certificate data. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will attempt to find the certificate identified by * Subject * . This can be either a complete or a substring match of the X.509 certificate's subject Distinguished Name (DN). The * Subject * parameter can also take an MD5, SHA-1, or SHA-256 thumbprint of the certificate to load in a "Thumbprint=value" format. ```text public Certificate(CertStoreTypes storeType, byte[] store, string storePassword, byte[] encoded); ``` * StoreType * identifies the type of certificate store to use. See for descriptions of the different certificate stores. * Store * is a byte array containing the certificate data. * StorePassword * is the password used to protect the store. After the store has been successfully opened, the component will load * Encoded * as an X.509 certificate and search the opened store for a corresponding private key. # Firewall Type The firewall the component will connect through. ## Remarks When connecting through a firewall, this type is used to specify different properties of the firewall, such as the firewall [Host](#Firewall_f_Host) and the [FirewallType](#Firewall_f_FirewallType). The following fields are available: - [AutoDetect](#Firewall_f_AutoDetect) - [FirewallType](#Firewall_f_FirewallType) - [Host](#Firewall_f_Host) - [Password](#Firewall_f_Password) - [Port](#Firewall_f_Port) - [User](#Firewall_f_User) ## Fields **AutoDetect** *bool* Default: False Whether to automatically detect and use firewall system settings, if available. **FirewallType** *FirewallTypes* Default: 0 The type of firewall to connect through. The applicable values are as follows: | | | | --- | --- | | fwNone (0) | No firewall (default setting). | | fwTunnel (1) | Connect through a tunneling proxy. [Port](#Firewall_f_Port) is set to 80. | | fwSOCKS4 (2) | Connect through a SOCKS4 Proxy. [Port](#Firewall_f_Port) is set to 1080. | | fwSOCKS5 (3) | Connect through a SOCKS5 Proxy. [Port](#Firewall_f_Port) is set to 1080. | | fwSOCKS4A (10) | Connect through a SOCKS4A Proxy. [Port](#Firewall_f_Port) is set to 1080. | **Host** *string* Default: "" The name or IP address of the firewall (optional). If a [Host](#Firewall_f_Host) is given, the requested connections will be authenticated through the specified firewall when connecting. If this field is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, this field is set to the corresponding address. If the search is not successful, the component throws an exception. **Password** *string* Default: "" A password if authentication is to be used when connecting through the firewall. If [Host](#Firewall_f_Host) is specified, the [User](#Firewall_f_User) and [Password](#Firewall_f_Password) fields are used to connect and authenticate to the given firewall. If the authentication fails, the component throws an exception. **Port** *int* Default: 0 The Transmission Control Protocol (TCP) port for the firewall [Host](#Firewall_f_Host). See the description of the [Host](#Firewall_f_Host) field for details. NOTE: This field is set automatically when [FirewallType](#Firewall_f_FirewallType) is set to a valid value. See the description of the [FirewallType](#Firewall_f_FirewallType) field for details. **User** *string* Default: "" A username if authentication is to be used when connecting through a firewall. If [Host](#Firewall_f_Host) is specified, this field and the [Password](#Firewall_f_Password) field are used to connect and authenticate to the given [Firewall](#firewall-type). If the authentication fails, the component throws an exception. ## Constructors ```text public Firewall(); ``` # Header Type This is an HTTP header as it is received from the server. ## Remarks When a header is received through a Header event, it is parsed into a [Header](#header-type) type. This type contains a [Field](#Header_f_Field), and its corresponding [Value](#Header_f_Value). The following fields are available: - [Field](#Header_f_Field) - [Value](#Header_f_Value) ## Fields **Field** *string* Default: "" This field contains the name of the HTTP [Header](#header-type) (this is the same case as it is delivered). **Value** *string* Default: "" This field contains the [Header](#header-type) contents. ## Constructors ```text public Header(); ``` ```text public Header(string field, string value); ``` # MailOAuthSettings Type The settings used to authenticate with the service provider. ## Remarks This type is used to give the component the necessary information needed to complete the OAuth process. The following fields are available: - [AccessToken](#MailOAuthSettings_f_AccessToken) - [AuthorizationScope](#MailOAuthSettings_f_AuthorizationScope) - [ClientId](#MailOAuthSettings_f_ClientId) - [ClientSecret](#MailOAuthSettings_f_ClientSecret) - [RefreshToken](#MailOAuthSettings_f_RefreshToken) - [ReturnURL](#MailOAuthSettings_f_ReturnURL) - [ServerAuthURL](#MailOAuthSettings_f_ServerAuthURL) - [ServerTokenURL](#MailOAuthSettings_f_ServerTokenURL) ## Fields **AccessToken** *string* Default: "" The access token returned by the authorization server. This is set when the component makes a request to the token server. **AuthorizationScope** *string* Default: "" The scope request or response parameter used during authorization. **ClientId** *string* Default: "" The id of the client assigned when registering the application. **ClientSecret** *string* Default: "" The secret value for the client assigned when registering the application. **RefreshToken** *string* Default: "" Specifies the refresh token received from or sent to the authorization server. This field is set automatically if a refresh token is retrieved from the token server. If the OAuthAutomaticRefresh configuration setting is set to true, and the [GrantType](#MailOAuthSettings_f_GrantType) field is set to a grant that can use refresh tokens. **ReturnURL** *string* Default: "" The URL where the user (browser) returns after authenticating. This field is mapped to the *redirect_uri* parameter when making a request to the authorization server. Typically, this is automatically set by the component when using the embedded web server. If the OAuthWebServerPort or OAuthWebServerHost configuration settings is set, then this field should be set to match. If using the Web client profile, this should be set to the place where the authorization code will be parsed out of the response after the user finishes authorizing. **ServerAuthURL** *string* Default: "" The URL of the authorization server. **ServerTokenURL** *string* Default: "" The URL of the token server used to obtain the access token. ## Constructors ```text public MailOAuthSettings(); ``` # MessageRecipient Type This types describes the message recipient. ## Remarks This type describes who the message is sent to. It includes fields to denote the name and email address of the recipient of the message. The type of recipient must also be specified if the component is sending the message. The following fields are available: - [Address](#MessageRecipient_f_Address) - [Name](#MessageRecipient_f_Name) - [Options](#MessageRecipient_f_Options) - [RecipientType](#MessageRecipient_f_RecipientType) ## Fields **Address** *string* Default: "" This field contains the email address of the recipient. **Name** *string* Default: "" This field contains the name of the recipient. **Options** *string* Default: "" This field contains the recipient sending options (used only by SMTP). This must be a string of RFC-compliant recipient options (used by [SMTP](#smtp-component)). One type of option is a delivery status notification sent per recipient, which is specified by RFC 1891. ```text component.MessageRecipients(0).Options = "NOTIFY SUCCESS,FAILURE,DELAY"; ``` **RecipientType** *EmailRecipientTypes* Default: 0 This field contains the recipient type: To, Cc, or Bcc. ## Constructors ```text public MessageRecipient(); ``` ```text public MessageRecipient(string address); ``` ```text public MessageRecipient(string address, int recipientType); ``` # Config Settings ([SMTP](#smtp-component) Component) The component accepts one or more of the following *configuration settings*. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these *internal properties* is provided through the [Config](#config-method-smtp-component) method. ### SMTP Config Settings **AllowEmptyTo**: If set to True, then the SendTo property is not required.Normally, the [SendTo](#sendto-property-smtp-component) property is required to send a message. If [AllowEmptyTo](#AllowEmptyTo) is True, then this is not the case, and messages can be sent with just one or both of [Cc](#cc-property-smtp-component) and [BCc](#bcc-property-smtp-component) set. **AuthorizationIdentity**: The value to use as the authorization identity when SASL authentication is used.When [AuthMechanism](#authmechanism-property-smtp-component) is set to amXOAUTH2, you may use this configuration setting to specify an authorization identity to be used when authenticating. In the case of amXOAUTH2, this should be your OAUTH authorization string. For instance: ```plaintext Bearer ya29.AHES6ZRmS-8xPbpGetC1VbABJIBRdKm-c4X7wMVGAbgxdGt5q8Ts3Q ``` NOTE: When using amXOAUTH2, [User](#user-property-smtp-component) must be specified, but [Password](#password-property-smtp-component) is not required. **Charset**: When set, the message headers will be encoded using the specified Charset.This configuration setting is used to specify the "charset" to be used to encode the message headers. For example, to use UTF-8 you can set this property to "UTF-8". The default value is "" (empty string) in which case the headers will not be encoded. **FoldHeaders**: Tells the component whether to fold the headers.If True, the component will fold the headers if the headers are over a certain length. If False, the headers will be on one line regardless of length. NOTE: This is True by default. **Hello**: The argument for HELO (herald) command to the server (defaults to local host name).The [Hello](#Hello) property specifies a string to send to the [MailServer](#mailserver-property-smtp-component) at connection time as an argument to the SMTP *HELO* command. This generally identifies the host sending mail, and that is why the [Hello](#Hello) property defaults to the name of the local host. The property is provided in case the component does not accept the default value and a custom value (e.g., a fully qualified domain name) must be sent. If [AllowExtensions](#allowextensions-property-smtp-component) is True, the *EHLO* command will be sent instead of the *HELO* command. **KeepQueue**: If set to True, queued files are not deleted after a successful send.Normally, [ProcessQueue](#processqueue-method-smtp-component) deletes queued files after processing them. If [KeepQueue](#KeepQueue) is True, then the file extension is instead changed to ".sent" and the files are not deleted. **MaxHeaderLength**: Maximum length for headers to avoid line folding (default 80).The [MaxHeaderLength](#MaxHeaderLength) specifies the maximum line length supported by the mail delivery system. Any headers longer than [MaxHeaderLength](#MaxHeaderLength) are folded as specified in RFC 822. It is generally a good idea to use a [MaxHeaderLength](#MaxHeaderLength) of less than 100 bytes, although different mail relays and mail servers have different requirements for header lengths. **MessageHeadersString**: String representation of RFC822-encoded headers of the message.This setting holds the full headers of the message in RFC 822 format. Use this along with [TransferText](#TransferText) to store the entire message in RFC 822 format. **Example:** ```csharp smtp1.Send(); string rawMsg = smtp1.Config("MessageHeadersString") + smtp1.Config("TransferText"); ``` **MessageIdAlgorithm**: Determines the algorithm used to hash the random MessageId. The [MessageIdAlgorithm](#MessageIdAlgorithm) specifies which algorithm to use in the hash for the [MessageId](#messageid-property-smtp-component) when the property is set to "*". The default value is "SHA1". Possible values are as follows: - "MD5" - "SHA1" (default) - "SHA256" **OtherHeaders**: An RFC 822 compliant string consisting of extra headers.This is the same as the [OtherHeaders](#otherheaders-property-smtp-component) property. This configuration setting is exposed for use by components that are inherited from SMTP. **ReturnPath**: Sets the Return-Path to be used for sending email.This is the same as the [ReturnPath](#returnpath-property-smtp-component) property. This configuration setting is exposed for use by components that are inherited from SMTP. **SendRSET**: Whether to send RSET command.By default, the component will periodically send the *RSET* command to the server. Changing this configuration setting to False will prevent the *RSET* command from being sent. This can be useful when interacting with some servers that do not respond properly to the *RSET* command. **StopOnBccErrors**: Instructs the component to stop sending the message if the server does not acknowledge any of the BCCs.If this configuration setting is set to True, the component will fail the moment the server does not acknowledge a Bcc address. If it is set to False, an error will be fired for every Bcc that is not recognized by the server, but the message will be sent to the rest of the recipients. The default value is False. **StopOnCcErrors**: Instructs the component to stop sending the message if the server does not acknowledge any of the CCs.If this configuration setting is set to True, the component will fail the moment the server does not acknowledge a Cc address. If it is set to False, an error will be fired for every Cc that is not recognized by the server, but the message will be sent to the rest of the recipients. The default value is True. **StopOnToErrors**: Instructs the component to stop sending the message if the server does not acknowledge any of the TOs.If this configuration setting is set to True, the component will fail the moment the server does not acknowledge a To address. If it is set to False, an error will be fired for every To that is not recognized by the server, but the message will be sent to the rest of the recipients. The default value is True. **TransferText**: String representation of RFC822-encoded body of the message.This configuration setting holds the full body of the message in RFC 822 format. Use this along with [MessageHeadersString](#MessageHeadersString) to store the entire message in RFC 822 format. **Example:** ```csharp smtp1.Send(); string rawMsg = smtp1.Config("MessageHeadersString") + smtp1.Config("TransferText"); ``` ### TCPClient Config Settings **CloseStreamAfterTransfer**: If true, the component will close the upload or download stream after the transfer.This configuration setting determines whether the input or output stream is closed after the transfer completes. When set to True (default), all streams will be closed after a transfer is completed. To keep streams open after the transfer of data, set this to False. The default value is True. **ConnectionTimeout**: Sets a separate timeout value for establishing a connection.When set, this configuration setting allows you to specify a different timeout value for establishing a connection. Otherwise, the component will use [Timeout](#timeout-property-smtp-component) for establishing a connection and transmitting/receiving data. **EnableFallback**: Whether to try the other addresses the remote host resolves to when a connection attempt fails.When set to True and RemoteHost resolves to more than one address, the component will try the remaining addresses in turn if the connection to the first one fails, and only throws an exception once every address has been tried. The error reported is the one from the last attempt. Use [FallbackTimeout](#FallbackTimeout) to limit the total time spent. NOTE: Only addresses of the same IP version as the first one are tried, this setting does not fall back from IPv6 to IPv4. Selecting between IPv6 and IPv4 is done by [UseIPv6](#UseIPv6) when the host is resolved. This setting must be set before the connection is established. The default value for this setting is False. **FallbackTimeout**: The maximum time in milliseconds to spend on connection attempts when EnableFallback is enabled.This setting limits the total time that the component will spend on all of the connection attempts made when [EnableFallback](#EnableFallback) is enabled. The default value is 0, in which case each attempt uses the operating system's own connection timeout. NOTE: This setting only applies when [EnableFallback](#EnableFallback) is True. It is unrelated to [ConnectionTimeout](#ConnectionTimeout), which is specified in seconds and applies to the [Connected](#connected-property-smtp-component) operation as a whole. **FirewallAutoDetect**: Tells the component whether or not to automatically detect and use firewall system settings, if available.This configuration setting is provided for use by components that do not directly expose Firewall properties. **FirewallHost**: Name or IP address of firewall (optional).If a [FirewallHost](#FirewallHost) is given, requested connections will be authenticated through the specified firewall when connecting. If the [FirewallHost](#FirewallHost) setting is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, the [FirewallHost](#FirewallHost) setting is set to the corresponding address. If the search is not successful, an error is returned. NOTE: This setting is provided for use by components that do not directly expose Firewall properties. **FirewallHTTPVersion**: The HTTP version to be used when connecting through a tunneling proxy.When [FirewallType](#FirewallType) is set to a tunneling proxy, this setting dictates which HTTP version is used when connecting. **FirewallListener**: If true, the component binds to a SOCKS firewall as a server (TCPClient only).This entry is for TCPClient only and does not work for other components that descend from TCPClient. If this entry is set, the component acts as a server. RemoteHost and RemotePort are used to tell the SOCKS firewall in which address and port to listen to. The firewall rules may ignore RemoteHost, and it is recommended that RemoteHost be set to empty string in this case. RemotePort is the port in which the firewall will listen to. If set to 0, the firewall will select a random port. The binding (address and port) is provided through the [ConnectionStatus](#connectionstatus-event-smtp-component) event. The connection to the firewall is made by calling the [Connect](#connect-method-smtp-component) method. **FirewallPassword**: Password to be used if authentication is to be used when connecting through the firewall.If [FirewallHost](#FirewallHost) is specified, the [FirewallUser](#FirewallUser) and [FirewallPassword](#FirewallPassword) settings are used to connect and authenticate to the given firewall. If the authentication fails, the component throws an exception. NOTE: This setting is provided for use by components that do not directly expose Firewall properties. **FirewallPort**: The TCP port for the FirewallHost;.The [FirewallPort](#FirewallPort) is set automatically when [FirewallType](#FirewallType) is set to a valid value. NOTE: This configuration setting is provided for use by components that do not directly expose Firewall properties. **FirewallType**: Determines the type of firewall to connect through.Possible values are as follows: | | | | --- | --- | | 0 | No firewall (default setting). | | 1 | Connect through a tunneling proxy. [FirewallPort](#FirewallPort) is set to 80. | | 2 | Connect through a SOCKS4 Proxy. [FirewallPort](#FirewallPort) is set to 1080. | | 3 | Connect through a SOCKS5 Proxy. [FirewallPort](#FirewallPort) is set to 1080. | | 10 | Connect through a SOCKS4A Proxy. [FirewallPort](#FirewallPort) is set to 1080. | NOTE: This setting is provided for use by components that do not directly expose Firewall properties. **FirewallUser**: A user name if authentication is to be used connecting through a firewall.If the [FirewallHost](#FirewallHost) is specified, the [FirewallUser](#FirewallUser) and [FirewallPassword](#FirewallPassword) settings are used to connect and authenticate to the Firewall. If the authentication fails, the component throws an exception. NOTE: This setting is provided for use by components that do not directly expose Firewall properties. **KeepAliveInterval**: The retry interval, in milliseconds, to be used when a TCP keep-alive packet is sent and no response is received.When set, [TCPKeepAlive](#TCPKeepAlive) will automatically be set to True. A TCP keep-alive packet will be sent after a period of inactivity as defined by [KeepAliveTime](#KeepAliveTime). If no acknowledgment is received from the remote host, the keep-alive packet will be sent again. This configuration setting specifies the interval at which the successive keep-alive packets are sent in milliseconds. This system default if this value is not specified here is 1 second. NOTE: This value is not applicable in macOS. **KeepAliveTime**: The inactivity time in milliseconds before a TCP keep-alive packet is sent.When set, [TCPKeepAlive](#TCPKeepAlive) will automatically be set to True. By default, the operating system will determine the time a connection is idle before a Transmission Control Protocol (TCP) keep-alive packet is sent. This system default if this value is not specified here is 2 hours. In many cases, a shorter interval is more useful. Set this value to the desired interval in milliseconds. **Linger**: When set to True, connections are terminated gracefully.This property controls how a connection is closed. The default is True. In the case that Linger is True (default), two scenarios determine how long the connection will linger. In the first, if [LingerTime](#LingerTime) is 0 (default), the system will attempt to send pending data for a connection until the default IP timeout expires. In the second scenario, if [LingerTime](#LingerTime) is a positive value, the system will attempt to send pending data until the specified [LingerTime](#LingerTime) is reached. If this attempt fails, then the system will reset the connection. The default behavior (which is also the default mode for stream sockets) might result in a long delay in closing the connection. Although the component returns control immediately, the system could hold system resources until all pending data are sent (even after your application closes). Setting this property to False forces an immediate disconnection. If you know that the other side has received all the data you sent (e.g., by a client acknowledgment), setting this property to False might be the appropriate course of action. **LingerTime**: Time in seconds to have the connection linger. LingerTime is the time, in seconds, the socket connection will linger. This value is 0 by default, which means it will use the default IP timeout. **LocalHost**: The name of the local host through which connections are initiated or accepted. The [LocalHost](#localhost-property-smtp-component) setting contains the name of the local host as obtained by the *gethostname()* system call, or if the user has assigned an IP address, the value of that address. In multihomed hosts (machines with more than one IP interface), setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface. If the component is connected, the [LocalHost](#localhost-property-smtp-component) setting shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multihomed hosts (machines with more than one IP interface). **LocalPort**: The port in the local host where the component binds. This configuration setting must be set before a connection is attempted. It instructs the component to bind to a specific port (or communication endpoint) in the local machine. Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established. LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error. This configuration setting is useful when trying to connect to services that require a trusted port on the client side. An example is the remote shell (rsh) service in UNIX systems. **MaxLineLength**: The maximum amount of data to accumulate when no EOL is found.[MaxLineLength](#MaxLineLength) is the size of an internal buffer, which holds received data while waiting for an EOL string. If an EOL string is found in the input stream before [MaxLineLength](#MaxLineLength) bytes are received, the DataIn event is fired with the *EOL* parameter set to True, and the buffer is reset. If no EOL is found, and [MaxLineLength](#MaxLineLength) bytes are accumulated in the buffer, the DataIn event is fired with the *EOL* parameter set to False, and the buffer is reset. The minimum value for [MaxLineLength](#MaxLineLength) is 256 bytes. The default value is 2048 bytes. **MaxTransferRate**: The transfer rate limit in bytes per second.This configuration setting can be used to throttle outbound TCP traffic. Set this to the number of bytes to be sent per second. By default, this is not set and there is no limit. **ProxyExceptionsList**: A semicolon separated list of hosts and IPs to bypass when using a proxy.This configuration setting optionally specifies a semicolon-separated list of hostnames or IP addresses to bypass when a proxy is in use. When requests are made to hosts specified in this property, the proxy will not be used. For instance: *www.google.com;www.example.com* **TCPKeepAlive**: Determines whether or not the keep alive socket option is enabled.If set to True, the socket's keep-alive option is enabled and keep-alive packets will be sent periodically to maintain the connection. Set [KeepAliveTime](#KeepAliveTime) and [KeepAliveInterval](#KeepAliveInterval) to configure the timing of the keep-alive packets. NOTE: This value is not applicable in Java. **TcpNoDelay**: Whether or not to delay when sending packets. When set to True, the socket will send all data that are ready to send at once. When set to False, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm. By default, this configuration setting is set to False. **UseIPv6**: Whether to use IPv6.When set to *0* (default), the component will use IPv4 exclusively. When set to *1*, the component will use IPv6 exclusively. To instruct the component to prefer IPv6 addresses, but use IPv4 if IPv6 is not supported on the system, this setting should be set to *2*. The default value is *0*. Possible values are as follows: | | | | --- | --- | | 0 | IPv4 only | | 1 | IPv6 only | | 2 | IPv6 with IPv4 fallback | **UseNTLMv2**: Whether to use NTLM V2.When authenticating with NTLM, this setting specifies whether NTLM V2 is used. By default this value is True and NTLM V2 will be used. Set this to False to use NTLM V1. ### SSL Config Settings **CACertFilePaths**: The paths to CA certificate files when using Mono on Unix/Linux.This configuration setting specifies the paths on disk to certificate authority (CA) certificate files when using Mono on Unix/Linux. It is not applicable in any other circumstances. The value is formatted as a list of paths separated by semicolons. The component will check for the existence of each file in the order specified. When a file is found, the CA certificates within the file will be loaded and used to determine the validity of server or client certificates. The default value is as follows: */etc/ssl/ca-bundle.pem;/etc/pki/tls/certs/ca-bundle.crt;/etc/ssl/certs/ca-certificates.crt;/etc/pki/tls/cacert.pem* **LogSSLPackets**: Controls whether SSL packets are logged when using the internal security API.When [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal*, this configuration setting controls whether Secure Sockets Layer (SSL) packets should be logged. By default, this configuration setting is *False*, as it is useful only for debugging purposes. When enabled, SSL packet logs are output using the [SSLStatus](#sslstatus-event-smtp-component) event, which will fire each time an SSL packet is sent or received. Enabling this configuration setting has no effect if [SSLProvider](#sslprovider-property-smtp-component) is set to *Platform*. **ReuseSSLSession**: Determines if the SSL session is reused. If set to True, the component will reuse the context if and only if the following criteria are met: - The target host name is the same. - The system cache entry has not expired (default timeout is 10 hours). - The application process that calls the function is the same. - The logon session is the same. - The instance of the component is the same. **SSLCACerts**: A newline separated list of CA certificates to be included when performing an SSL handshake.When [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal*, this configuration setting specifies one or more CA certificates to be included with the [SSLCert](#sslcert-property-smtp-component) property. Some servers or clients require the entire chain, including CA certificates, to be presented when performing SSL authentication. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance: ```text -----BEGIN CERTIFICATE----- MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw ... Intermediate Cert ... eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w F0I1XhM+pKj7FjDr+XNj -----END CERTIFICATE----- \r \n -----BEGIN CERTIFICATE----- MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp ... Root Cert ... d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA -----END CERTIFICATE----- ``` **SSLCheckCRL**: Whether to check the Certificate Revocation List for the server certificate.This configuration setting specifies whether the component will check the Certificate Revocation List (CRL) specified by the server certificate. If set to 1 or 2, the component will first obtain the list of CRL URLs from the server certificate's CRL distribution points extension. The component will then make HTTP requests to each CRL endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation the component throws an exception. When set to 0 (default), the CRL check will not be performed by the component. When set to 1, it will attempt to perform the CRL check, but it will continue without an error if the server's certificate does not support CRL. When set to 2, it will perform the CRL check and will throw an error if CRL is not supported. This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems. **SSLCheckOCSP**: Whether to use OCSP to check the status of the server certificate.This configuration setting specifies whether the component will use OCSP to check the validity of the server certificate. If set to 1 or 2, the component will first obtain the Online Certificate Status Protocol (OCSP) URL from the server certificate's OCSP extension. The component will then locate the issuing certificate and make an HTTP request to the OCSP endpoint to check the validity of the server's certificate. If the certificate has been revoked or any other issues are found during validation, the component throws an exception. When set to 0 (default), the component will not perform an OCSP check. When set to 1, it will attempt to perform the OCSP check, but it will continue without an error if the server's certificate does not support OCSP. When set to 2, it will perform the OCSP check and will throw an error if OCSP is not supported. This configuration setting is supported only in the Java, C#, and C++ editions. In the C++ edition, it is supported only on Windows operating systems. **SSLCipherStrength**: The minimum cipher strength used for bulk encryption. This minimum cipher strength is largely dependent on the security modules installed on the system. If the cipher strength specified is not supported, an error will be returned when connections are initiated. NOTE: This configuration setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the [SSLStatus](#sslstatus-event-smtp-component) event. Use this configuration setting with caution. Requesting a lower cipher strength than necessary could potentially cause serious security vulnerabilities in your application. When the provider is OpenSSL, [SSLCipherStrength](#SSLCipherStrength) is currently not supported. This functionality is instead made available through the [OpenSSLCipherList](#OpenSSLCipherList) configuration setting. **SSLClientCACerts**: A newline separated list of CA certificates to use during SSL client certificate validation.This configuration setting is only applicable to server components (e.g., TCPServer) see [SSLServerCACerts](#SSLServerCACerts) for client components (e.g., TCPClient). This setting can be used to optionally specify one or more CA certificates to be used when verifying the client certificate that is presented by the client during the SSL handshake when SSLAuthenticateClients is enabled. When verifying the client's certificate, the certificates trusted by the system will be used as part of the verification process. If the client's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the client's CA certificates are not already trusted on the system and cannot be installed to the trusted system store. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance: ```text -----BEGIN CERTIFICATE----- MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw ... Intermediate Cert ... eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w F0I1XhM+pKj7FjDr+XNj -----END CERTIFICATE----- \r \n -----BEGIN CERTIFICATE----- MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp ... Root Cert ... d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA -----END CERTIFICATE----- ``` **SSLEnabledCipherSuites**: The cipher suite to be used in an SSL negotiation.This configuration setting enables the cipher suites to be used in SSL negotiation. By default, the enabled cipher suites will include all available ciphers ("*"). The special value "*" means that the component will pick all of the supported cipher suites. If [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) is set to any other value, only the specified cipher suites will be considered. Multiple cipher suites are separated by semicolons. Example values when [SSLProvider](#sslprovider-property-smtp-component) is set to *Platform* include the following: ```text obj.config("SSLEnabledCipherSuites=*"); obj.config("SSLEnabledCipherSuites=CALG_AES_256"); obj.config("SSLEnabledCipherSuites=CALG_AES_256;CALG_3DES"); ``` Possible values when [SSLProvider](#sslprovider-property-smtp-component) is set to *Platform* include the following: - CALG_3DES - CALG_3DES_112 - CALG_AES - CALG_AES_128 - CALG_AES_192 - CALG_AES_256 - CALG_AGREEDKEY_ANY - CALG_CYLINK_MEK - CALG_DES - CALG_DESX - CALG_DH_EPHEM - CALG_DH_SF - CALG_DSS_SIGN - CALG_ECDH - CALG_ECDH_EPHEM - CALG_ECDSA - CALG_ECMQV - CALG_HASH_REPLACE_OWF - CALG_HUGHES_MD5 - CALG_HMAC - CALG_KEA_KEYX - CALG_MAC - CALG_MD2 - CALG_MD4 - CALG_MD5 - CALG_NO_SIGN - CALG_OID_INFO_CNG_ONLY - CALG_OID_INFO_PARAMETERS - CALG_PCT1_MASTER - CALG_RC2 - CALG_RC4 - CALG_RC5 - CALG_RSA_KEYX - CALG_RSA_SIGN - CALG_SCHANNEL_ENC_KEY - CALG_SCHANNEL_MAC_KEY - CALG_SCHANNEL_MASTER_HASH - CALG_SEAL - CALG_SHA - CALG_SHA1 - CALG_SHA_256 - CALG_SHA_384 - CALG_SHA_512 - CALG_SKIPJACK - CALG_SSL2_MASTER - CALG_SSL3_MASTER - CALG_SSL3_SHAMD5 - CALG_TEK - CALG_TLS1_MASTER - CALG_TLS1PRF Example values when [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal*include the following: ```text obj.config("SSLEnabledCipherSuites=*"); obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA"); obj.config("SSLEnabledCipherSuites=TLS_DHE_DSS_WITH_AES_128_CBC_SHA;TLS_ECDH_RSA_WITH_AES_128_CBC_SHA"); ``` Possible values when [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal* include the following: - TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 - TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 - TLS_RSA_WITH_AES_256_GCM_SHA384 - TLS_RSA_WITH_AES_128_GCM_SHA256 - TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 - TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 - TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 - TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 - TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 - TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 - TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 - TLS_RSA_WITH_AES_256_CBC_SHA256 - TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 - TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 - TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 - TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - TLS_RSA_WITH_AES_128_CBC_SHA256 - TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 - TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 - TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 - TLS_RSA_WITH_AES_256_CBC_SHA - TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA - TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA - TLS_DHE_RSA_WITH_AES_256_CBC_SHA - TLS_ECDH_RSA_WITH_AES_256_CBC_SHA - TLS_DHE_DSS_WITH_AES_256_CBC_SHA - TLS_RSA_WITH_AES_128_CBC_SHA - TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA - TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA - TLS_ECDH_RSA_WITH_AES_128_CBC_SHA - TLS_DHE_RSA_WITH_AES_128_CBC_SHA - TLS_DHE_DSS_WITH_AES_128_CBC_SHA - TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA - TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA - TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA - TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA - TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA - TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA - TLS_RSA_WITH_3DES_EDE_CBC_SHA - TLS_RSA_WITH_DES_CBC_SHA - TLS_DHE_RSA_WITH_DES_CBC_SHA - TLS_DHE_DSS_WITH_DES_CBC_SHA - TLS_RSA_WITH_RC4_128_MD5 - TLS_RSA_WITH_RC4_128_SHA When TLS 1.3 is negotiated (see [SSLEnabledProtocols](#SSLEnabledProtocols)), only the following cipher suites are supported: - TLS_AES_256_GCM_SHA384 - TLS_CHACHA20_POLY1305_SHA256 - TLS_AES_128_GCM_SHA256 [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) is used together with [SSLCipherStrength](#SSLCipherStrength). **SSLEnabledProtocols**: Used to enable/disable the supported security protocols.This configuration setting is used to enable or disable the supported security protocols. Not all supported protocols are enabled by default. The default value is *4032* for client components, and *3072* for server components. To specify a combination of enabled protocol versions set this config to the binary *OR* of one or more of the following values: | | | | --- | --- | | TLS1.3 | 12288 (Hex 3000) | | TLS1.2 | 3072 (Hex C00) (Default - Client and Server) | | TLS1.1 | 768 (Hex 300) (Default - Client) | | TLS1 | 192 (Hex C0) (Default - Client) | | SSL3 | 48 (Hex 30) | | SSL2 | 12 (Hex 0C) | Note that only TLS 1.2 is enabled for server components that accept incoming connections. This adheres to industry standards to ensure a secure connection. Client components enable TLS 1.0, TLS 1.1, and TLS 1.2 by default and will negotiate the highest mutually supported version when connecting to a server, which should be TLS 1.2 in most cases. **SSLEnabledProtocols: Transport Layer Security (TLS) 1.3 Notes:** By default when TLS 1.3 is enabled, the component will first try to use the platform TLS 1.3 implementation when the [SSLProvider](#sslprovider-property-smtp-component) is set to Automatic for all editions. If the platform TLS 1.3 implementation is not available, the internal implementation will be used. In editions that are designed to run on Windows, [SSLProvider](#sslprovider-property-smtp-component) can be set to Platform to use the platform implementation instead of the internal implementation. When configured in this manner, please note that the platform provider is supported only on Windows 11/Windows Server 2022 and up. The default internal provider is available on all platforms and is not restricted to any specific OS version. If set to *1* (Platform provider), please be aware of the following notes: - The platform provider is available only on Windows 11/Windows Server 2022 and up. - [SSLEnabledCipherSuites](#SSLEnabledCipherSuites) and other similar SSL configuration settings are not supported. - If [SSLEnabledProtocols](#SSLEnabledProtocols) includes both TLS 1.3 and TLS 1.2, these restrictions are still applicable even if TLS 1.2 is negotiated. Enabling TLS 1.3 with the platform provider changes the implementation used for all TLS versions. **SSLEnabledProtocols: SSL2 and SSL3 Notes: ** SSL 2.0 and 3.0 are not supported by the component when the [SSLProvider](#sslprovider-property-smtp-component) is set to internal. To use SSL 2.0 or SSL 3.0, the platform security API must have the protocols enabled and [SSLProvider](#sslprovider-property-smtp-component) needs to be set to platform. **SSLEnableRenegotiation**: Whether the renegotiation_info SSL extension is supported.This configuration setting specifies whether the renegotiation_info SSL extension will be used in the request when using the internal security API. This configuration setting is *false* by default, but it can be set to *true* to enable the extension. This configuration setting is applicable only when [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal*. **SSLIncludeCertChain**: Whether the entire certificate chain is included in the SSLServerAuthentication event.This configuration setting specifies whether the Encoded parameter of the [SSLServerAuthentication](#sslserverauthentication-event-smtp-component) event contains the full certificate chain. By default this value is False and only the leaf certificate will be present in the Encoded parameter of the [SSLServerAuthentication](#sslserverauthentication-event-smtp-component) event. If set to True, all certificates returned by the server will be present in the Encoded parameter of the [SSLServerAuthentication](#sslserverauthentication-event-smtp-component) event. This includes the leaf certificate, any intermediate certificate, and the root certificate. Note: When [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal* this value is automatically set to *true*. This is needed for proper validation when using the internal provider. **SSLKeyLogFile**: The location of a file where per-session secrets are written for debugging purposes.This configuration setting optionally specifies the full path to a file on disk where per-session secrets are stored for debugging purposes. When set, the component will save the session secrets in the same format as the SSLKEYLOGFILE environment variable functionality used by most major browsers and tools, such as Chrome, Firefox, and cURL. This file can then be used in tools such as Wireshark to decrypt TLS traffic for debugging purposes. When writing to this file, the component will only append, it will not overwrite previous values. NOTE: This configuration setting is applicable only when [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal*. **SSLNegotiatedCipher**: Returns the negotiated cipher suite.This configuration setting returns the cipher suite negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedCipher[connId]"); ``` **SSLNegotiatedCipherStrength**: Returns the negotiated cipher suite strength.This configuration setting returns the strength of the cipher suite negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedCipherStrength[connId]"); ``` **SSLNegotiatedCipherSuite**: Returns the negotiated cipher suite.This configuration setting returns the cipher suite negotiated during the SSL handshake represented as a single string. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedCipherSuite[connId]"); ``` **SSLNegotiatedKeyExchange**: Returns the negotiated key exchange algorithm.This configuration setting returns the key exchange algorithm negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedKeyExchange[connId]"); ``` **SSLNegotiatedKeyExchangeStrength**: Returns the negotiated key exchange algorithm strength.This configuration setting returns the strength of the key exchange algorithm negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedKeyExchangeStrength[connId]"); ``` **SSLNegotiatedVersion**: Returns the negotiated protocol version.This configuration setting returns the protocol version negotiated during the SSL handshake. NOTE: For server components (e.g., TCPServer), this is a per-connection configuration setting accessed by passing the ConnectionId. For example: ```csharp server.Config("SSLNegotiatedVersion[connId]"); ``` **SSLSecurityFlags**: Flags that control certificate verification.The following flags are defined (specified in hexadecimal notation). They can be ORed together to exclude multiple conditions: | | | | --- | --- | | 0x00000001 | Ignore time validity status of certificate. | | 0x00000002 | Ignore time validity status of CTL. | | 0x00000004 | Ignore non-nested certificate times. | | 0x00000010 | Allow unknown certificate authority. | | 0x00000020 | Ignore wrong certificate usage. | | 0x00000100 | Ignore unknown certificate revocation status. | | 0x00000200 | Ignore unknown CTL signer revocation status. | | 0x00000400 | Ignore unknown certificate authority revocation status. | | 0x00000800 | Ignore unknown root revocation status. | | 0x00008000 | Allow test root certificate. | | 0x00004000 | Trust test root certificate. | | 0x80000000 | Ignore non-matching CN (certificate CN non-matching server name). | This functionality is currently not available in Java or when the provider is OpenSSL. **SSLServerCACerts**: A newline separated list of CA certificates to use during SSL server certificate validation.This configuration setting is only used by client components (e.g., TCPClient) see [SSLClientCACerts](#SSLClientCACerts) for server components (e.g., TCPServer). This configuration setting can be used to optionally specify one or more CA certificates to be used when connecting to the server and verifying the server certificate. When verifying the server's certificate, the certificates trusted by the system will be used as part of the verification process. If the server's CA certificates are not installed to the trusted system store, they may be specified here so they are included when performing the verification process. This configuration setting should be set only if the server's CA certificates are not already trusted on the system and cannot be installed to the trusted system store. The value of this configuration setting is a newline-separated (CR/LF) list of certificates. For instance: ```text -----BEGIN CERTIFICATE----- MIIEKzCCAxOgAwIBAgIRANTET4LIkxdH6P+CFIiHvTowDQYJKoZIhvcNAQELBQAw ... Intermediate Cert... eWHV5OW1K53o/atv59sOiW5K3crjFhsBOd5Q+cJJnU+SWinPKtANXMht+EDvYY2w F0I1XhM+pKj7FjDr+XNj -----END CERTIFICATE----- \r \n -----BEGIN CERTIFICATE----- MIIEFjCCAv6gAwIBAgIQetu1SMxpnENAnnOz1P+PtTANBgkqhkiG9w0BAQUFADBp ... Root Cert... d8q23djXZbVYiIfE9ebr4g3152BlVCHZ2GyPdjhIuLeH21VbT/dyEHHA -----END CERTIFICATE----- ``` **TLS12SignatureAlgorithms**: Defines the allowed TLS 1.2 signature algorithms when SSLProvider is set to Internal.This configuration setting specifies the allowed server certificate signature algorithms when [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal* and [SSLEnabledProtocols](#SSLEnabledProtocols) is set to allow TLS 1.2. When specified the component will verify that the server certificate signature algorithm is among the values specified in this configuration setting. If the server certificate signature algorithm is unsupported, the component throws an exception. The format of this value is a comma-separated list of hash-signature combinations. For instance: ```csharp component.SSLProvider = TCPClientSSLProviders.sslpInternal; component.Config("SSLEnabledProtocols=3072"); //TLS 1.2 component.Config("TLS12SignatureAlgorithms=sha256-rsa,sha256-dsa,sha1-rsa,sha1-dsa"); ``` The default value for this configuration setting is *sha512-ecdsa,sha512-rsa,sha512-dsa,sha384-ecdsa,sha384-rsa,sha384-dsa,sha256-ecdsa,sha256-rsa,sha256-dsa,sha224-ecdsa,sha224-rsa,sha224-dsa,sha1-ecdsa,sha1-rsa,sha1-dsa*. To not restrict the server's certificate signature algorithm, specify an empty string as the value for this configuration setting, which will cause the signature_algorithms TLS 1.2 extension to not be sent. **TLS12SupportedGroups**: The supported groups for ECC.This configuration setting specifies a comma-separated list of named groups used in TLS 1.2 for ECC. The default value is *ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1*. When using TLS 1.2 and [SSLProvider](#sslprovider-property-smtp-component) is set to *Internal*, the values refer to the supported groups for ECC. The following values are supported: - "ecdhe_secp256r1" (default) - "ecdhe_secp384r1" (default) - "ecdhe_secp521r1" (default) **TLS13KeyShareGroups**: The groups for which to pregenerate key shares.This configuration setting specifies a comma-separated list of named groups used in TLS 1.3 for key exchange. The groups specified here will have key share data pregenerated locally before establishing a connection. This can prevent an additional roundtrip during the handshake if the group is supported by the server. The default value is set to balance common supported groups and the computational resources required to generate key shares. As a result, only some groups are included by default in this configuration setting. NOTE: All supported groups can always be used during the handshake even if not listed here, but if a group is used that is not present in this list, it will incur an additional roundtrip and time to generate the key share for that group. In most cases, this configuration setting does not need to be modified. This should be modified only if there is a specific reason to do so. The default value is *ecdhe_x25519,ecdhe_secp256r1,ecdhe_secp384r1,ffdhe_2048,ffdhe_3072* The values are ordered from most preferred to least preferred. The following values are supported: - "ecdhe_x25519" (default) - "ecdhe_x448" - "ecdhe_secp256r1" (default) - "ecdhe_secp384r1" (default) - "ecdhe_secp521r1" - "ffdhe_2048" (default) - "ffdhe_3072" (default) - "ffdhe_4096" - "ffdhe_6144" - "ffdhe_8192" **TLS13SignatureAlgorithms**: The allowed certificate signature algorithms.This configuration setting holds a comma-separated list of allowed signature algorithms. Possible values include the following: - "ed25519" (default) - "ed448" (default) - "ecdsa_secp256r1_sha256" (default) - "ecdsa_secp384r1_sha384" (default) - "ecdsa_secp521r1_sha512" (default) - "rsa_pkcs1_sha256" (default) - "rsa_pkcs1_sha384" (default) - "rsa_pkcs1_sha512" (default) - "rsa_pss_sha256" (default) - "rsa_pss_sha384" (default) - "rsa_pss_sha512" (default) The default value is *rsa_pss_sha256,rsa_pss_sha384,rsa_pss_sha512,rsa_pkcs1_sha256,rsa_pkcs1_sha384,rsa_pkcs1_sha512,ecdsa_secp256r1_sha256,ecdsa_secp384r1_sha384,ecdsa_secp521r1_sha512,ed25519,ed448*. This configuration setting is applicable only when [SSLEnabledProtocols](#SSLEnabledProtocols) includes TLS 1.3. **TLS13SupportedGroups**: The supported groups for (EC)DHE key exchange.This configuration setting specifies a comma-separated list of named groups used in TLS 1.3 for key exchange. This configuration setting should be modified only if there is a specific reason to do so. The default value is *ecdhe_x25519,ecdhe_x448,ecdhe_secp256r1,ecdhe_secp384r1,ecdhe_secp521r1,ffdhe_2048,ffdhe_3072,ffdhe_4096,ffdhe_6144,ffdhe_8192,mlkem_512,mlkem_768,mlkem_1024,x25519_mlkem_768,secp256r1_mlkem_768* The values are ordered from most preferred to least preferred. The following values are supported: - "ecdhe_x25519" (default) - "ecdhe_x448" (default) - "ecdhe_secp256r1" (default) - "ecdhe_secp384r1" (default) - "ecdhe_secp521r1" (default) - "ffdhe_2048" (default) - "ffdhe_3072" (default) - "ffdhe_4096" (default) - "ffdhe_6144" (default) - "ffdhe_8192" (default) - "mlkem_512" (default) - "mlkem_768" (default) - "mlkem_1024" (default) - "x25519_mlkem_768" (default) - "secp256r1_mlkem_768" (default) Post-quantum algorithms (*mlkem_512,mlkem_768,mlkem_1024,x25519_mlkem_768,secp256r1_mlkem_768*) in our components rely on the operating system's underlying cryptographic primitives. The following platforms are currently supported: - Windows Server 2025 - Windows 11 24H2 - Windows 11 25H2 ### Socket Config Settings **AbsoluteTimeout**: Determines whether timeouts are inactivity timeouts or absolute timeouts.If [AbsoluteTimeout](#AbsoluteTimeout) is set to True, any method that does not complete within [Timeout](#timeout-property-smtp-component) seconds will be aborted. By default, *AbsoluteTimeout* is False, and the timeout is an inactivity timeout. NOTE: This option is not valid for User Datagram Protocol (UDP) ports. **FirewallData**: Used to send extra data to the firewall.When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g., headers for custom authentication schemes). **InBufferSize**: The size in bytes of the incoming queue of the socket.This is the size of an internal queue in the Transmission Control Protocol (TCP)/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. In some cases, increasing the value of the *InBufferSize* setting can provide significant improvements in performance. Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the *InBufferSize* reverts to its defined size. The same happens if you attempt to make it too large or too small. **OutBufferSize**: The size in bytes of the outgoing queue of the socket.This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. In some cases, increasing the value of the *OutBufferSize* setting can provide significant improvements in performance. Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the *OutBufferSize* reverts to its defined size. The same happens if you attempt to make it too large or too small. ### Base Config Settings **BuildInfo**: Information about the product's build.When queried, this setting will return a string containing information about the product's build. **GUIAvailable**: Whether or not a message loop is available for processing events.In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation. In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting [GUIAvailable](#GUIAvailable) to *false* will ensure that the component does not attempt to process external events. **LicenseInfo**: Information about the current license.When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information: - Product: The product the license is for. - Product Key: The key the license was generated from. - License Source: Where the license was found (e.g., RuntimeLicense, License File). - License Type: The type of license installed (e.g., Royalty Free, Single Server). - Last Valid Build: The last valid build number for which the license will work. **MaskSensitiveData**: Whether sensitive data is masked in log messages.In certain circumstances it may be beneficial to mask sensitive data, like passwords, in log messages. Set this to *true* to mask sensitive data. The default is *true*. **UseFIPSCompliantAPI**: Tells the component whether or not to use FIPS certified APIs.When set to *true*, the component will utilize the underlying operating system's certified APIs. Java editions, regardless of OS, utilize Bouncy Castle Federal Information Processing Standards (FIPS), while all other Windows editions make use of Microsoft security libraries. FIPS mode can be enabled by setting the *UseFIPSCompliantAPI* configuration setting to *true*. This is a static setting that applies to all instances of all components of the toolkit within the process. It is recommended to enable or disable this setting once before the component has been used to establish a connection. Enabling FIPS while an instance of the component is active and connected may result in unexpected behavior. For more details, please see the [FIPS 140-2 Compliance](https://www.nsoftware.com/kb/articles/fips.rst) article. NOTE: This setting is applicable only on Windows. NOTE: Enabling FIPS compliance requires a special license; please contact [sales@nsoftware.com](mailto:sales@nsoftware.com) for details. **UseInternalSecurityAPI**: Whether or not to use the system security libraries or an internal implementation. When set to *false*, the component will use the system security libraries by default to perform cryptographic functions where applicable. In this case, calls to unmanaged code will be made. In certain environments, this is not desirable. To use a completely managed security implementation, set this setting to *true*. Setting this configuration setting to *true* tells the component to use the internal implementation instead of using the system security libraries. On Windows, this setting is set to *false* by default. On Linux/macOS, this setting is set to *true* by default. NOTE: This setting is static. The value set is applicable to all components used in the application. When this value is set, the product's system dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file. # Trappable Errors ([SMTP](#smtp-component) Component) ### SMTP Errors | | | | --- | --- | | 118 | Firewall Error. Error message contains detailed description. | | 161 | SMTP protocol error. Description contains the server reply. | | 162 | Error communicating with server. Error text is attached. | | 163 | Please specify a [MailServer](#mailserver-property-smtp-component). | | 164 | Please specify a sender ([From](#from-property-smtp-component)). | | 165 | Please specify a recipient. | | 166 | Busy executing current method. | | 301 | Operation interrupted. | | 302 | Cannot open AttachedFile. | The component may also return one of the following error codes, which are inherited from other components. ### TCPClient Errors | | | | --- | --- | | 100 | You cannot change the RemotePort at this time. A connection is in progress. | | 101 | You cannot change the RemoteHost (Server) at this time. A connection is in progress. | | 102 | The RemoteHost address is invalid (0.0.0.0). | | 104 | Already connected. If you want to reconnect, close the current connection first. | | 106 | You cannot change the LocalPort at this time. A connection is in progress. | | 107 | You cannot change the [LocalHost](#localhost-property-smtp-component) at this time. A connection is in progress. | | 112 | You cannot change [MaxLineLength](#MaxLineLength) at this time. A connection is in progress. | | 116 | RemotePort cannot be zero. Please specify a valid service port number. | | 117 | You cannot change the UseConnection option while the component is active. | | 135 | Operation would block. | | 201 | Timeout. | | 211 | Action impossible in control's present state. | | 212 | Action impossible while not connected. | | 213 | Action impossible while listening. | | 301 | Timeout. | | 303 | Could not open file. | | 434 | Unable to convert string to selected CodePage. | | 1105 | Already connecting. If you want to reconnect, close the current connection first. | | 1117 | You need to connect first. | | 1119 | You cannot change the LocalHost at this time. A connection is in progress. | | 1120 | Connection dropped by remote host. | ### TCP/IP Errors | | | | --- | --- | | 10004 | [10004] Interrupted system call. | | 10009 | [10009] Bad file number. | | 10013 | [10013] Access denied. | | 10014 | [10014] Bad address. | | 10022 | [10022] Invalid argument. | | 10024 | [10024] Too many open files. | | 10035 | [10035] Operation would block. | | 10036 | [10036] Operation now in progress. | | 10037 | [10037] Operation already in progress. | | 10038 | [10038] Socket operation on nonsocket. | | 10039 | [10039] Destination address required. | | 10040 | [10040] Message is too long. | | 10041 | [10041] Protocol wrong type for socket. | | 10042 | [10042] Bad protocol option. | | 10043 | [10043] Protocol is not supported. | | 10044 | [10044] Socket type is not supported. | | 10045 | [10045] Operation is not supported on socket. | | 10046 | [10046] Protocol family is not supported. | | 10047 | [10047] Address family is not supported by protocol family. | | 10048 | [10048] Address already in use. | | 10049 | [10049] Cannot assign requested address. | | 10050 | [10050] Network is down. | | 10051 | [10051] Network is unreachable. | | 10052 | [10052] Net dropped connection or reset. | | 10053 | [10053] Software caused connection abort. | | 10054 | [10054] Connection reset by peer. | | 10055 | [10055] No buffer space available. | | 10056 | [10056] Socket is already connected. | | 10057 | [10057] Socket is not connected. | | 10058 | [10058] Cannot send after socket shutdown. | | 10059 | [10059] Too many references, cannot splice. | | 10060 | [10060] Connection timed out. | | 10061 | [10061] Connection refused. | | 10062 | [10062] Too many levels of symbolic links. | | 10063 | [10063] File name is too long. | | 10064 | [10064] Host is down. | | 10065 | [10065] No route to host. | | 10066 | [10066] Directory is not empty | | 10067 | [10067] Too many processes. | | 10068 | [10068] Too many users. | | 10069 | [10069] Disc Quota Exceeded. | | 10070 | [10070] Stale NFS file handle. | | 10071 | [10071] Too many levels of remote in path. | | 10091 | [10091] Network subsystem is unavailable. | | 10092 | [10092] WINSOCK DLL Version out of range. | | 10093 | [10093] Winsock is not loaded yet. | | 11001 | [11001] Host not found. | | 11002 | [11002] Nonauthoritative 'Host not found' (try again or check DNS setup). | | 11003 | [11003] Nonrecoverable errors: FORMERR, REFUSED, NOTIMP. | | 11004 | [11004] Valid name, no data record (check DNS setup). |