PSMTP Configuration

OpenPGP messages may contain a comment. A comment may optionally be set before calling Encrypt, Sign, or SignAndEncrypt.

This setting controls whether or not a cleartext signature is created during signing. The default value is True. When set to True a cleartext signature will be created when Sign is called.

Note: some mail applications such as GpgOL cannot process cleartext signatures.

This setting controls whether attachments are processed when calling Encrypt, Sign, or SignAndEncrypt. If set to True the attachments will also be encrypted and/or signed. If set to False the attachments will be added to the message with no additional processing. The default value is False.

This setting controls the level of detail that is logged through the Status event. Possible values are:

When set to true the component will automatically select an appropriate hash algorithm for DSA keys. DSA requires that the hash be 160 bits or larger. This means the MD5 hash algorithm is not a valid option. The default value is True.

This setting specifies the level of compression to be used: possible values are 1 to 6. Higher values will cause the component to compress better; lower values will cause the component to compress faster. The default value is 4. Note: This setting is only applicable when CompressionMethod is set to "zlib" or "zip".

This setting specifies the passphrase when using symmetric encryption. If a value is provided, symmetric encryption/decryption will be attempted. In this case no keys are used for either encryption or decryption. Only Encrypt and Decrypt are valid operations when a value is set. Sign, SignAndEncrypt, VerifySignature, and DecryptAndVerifySignature are not valid operations when using this option.

This setting specifies the Version header value included in the ASCII armored OpenPGP message. This may be set before calling Encrypt, Sign, or SignAndEncrypt. The default value is "IPWorks! OpenPGP v9.0".

This setting will be populated after calling Decrypt, VerifySignature, or DecryptAndVerifySignature.

Normally, the SendTo property is required to send a message. If AllowEmptyTo is True, then this is not the case, and messages can be sent with just one or both of Cc and BCc set.

When AuthMechanism is set to amXOAUTH2 you may use this 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:

Bearer ya29.AHES6ZRmS-8xPbpGetC1VbABJIBRdKm-c4X7wMVGAbgxdGt5q8Ts3Q

This property 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.

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 that this is True by default.

The Hello property specifies a string to send to the MailServer at connection time as an argument to the SMTP HELO command. This generally identifies the host sending mail, and that's why the 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 (such as, for example, a fully qualified domain name) must be sent.

If AllowExtensions is True the EHLO command will be sent instead of the HELO command.

Normally, ProcessQueue deletes queued files after processing them. If KeepQueue is True, the file extension is instead changed to ".sent" and the files are not deleted.

The MaxHeaderLength specifies the maximum line length supported by the mail delivery system. Any headers longer than MaxHeaderLength are folded as specified in RFC 822.

It is generally a good idea to use a MaxHeaderLength of less than 100 bytes, although different mail relays and mail servers have different requirements for header lengths.

The MessageIdAlgorithm specifies which algorithm to use in the hash for the MessageId when the property is set to "*". The default value is "MD5".

Possible values are:

• "MD5" (default)
• "SHA1"

This is the same as the OtherHeaders property. This setting is exposed here for use by components that inherit from SMTP.

This is the same as the ReturnPath property. This setting is exposed here for use by components that inherit from SMTP.

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.

If this setting is set to True, the component will fail the moment the server does not acknowledge a To address. If 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.

If this setting is set to True, the component will fail the moment the server does not acknowledge a Cc address. If 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.

If this setting is set to True, the component will fail the moment the server does not acknowledge a Bcc address. If 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.

When set, this configuration setting allows you to specify a different timeout value for establishing a connection. Otherwise, the component will use Timeout for establishing a connection and transmitting/receiving data.

This is the same as AutoDetect. This setting is provided for use by components that do not directly expose Firewall properties.

If a FirewallHost is given, requested connections will be authenticated through the specified firewall when connecting.

If the FirewallHost setting is set to a Domain Name, a DNS request is initiated. Upon successful termination of the request, the FirewallHost setting is set to the corresponding address. If the search is not successful, an error is returned.

NOTE: This is the same as Host. This setting is provided for use by components that do not directly expose Firewall properties.

This entry is for IPPort only and does not work for other components that descend from IPPort.

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 event.

The connection to the firewall is made by calling the Connect method.

If FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the given firewall. If the authentication fails, the component throws an exception.

NOTE: This is the same as Password. This setting is provided for use by components that do not directly expose Firewall properties.

Note that the FirewallPort is set automatically when FirewallType is set to a valid value.

NOTE: This is the same as Port. This setting is provided for use by components that do not directly expose Firewall properties.

The appropriate values are as follows:

NOTE: This is the same as FirewallType. This setting is provided for use by components that do not directly expose Firewall properties.

If the FirewallHost is specified, the FirewallUser and FirewallPassword settings are used to connect and authenticate to the Firewall. If the authentication fails, the component throws an exception.

NOTE: This is the same as User. This setting is provided for use by components that do not directly expose Firewall properties.

When set, TCPKeepAlive will automatically be set to true. By default the operating system will determine the time a connection is idle before a 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.

Note: This value is not applicable in Java.

When set, TCPKeepAlive will automatically be set to true. A TCP keep-alive packet will be sent after a period of inactivity as defined by KeepAliveTime. If no acknowledgement is received from the remote host the keep-alive packet will be re-sent. This 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 Java or MAC.

This property controls how a connection is closed. The default is True.

In the case that Linger is True (default), there are two scenarios for determining how long the connection will linger. The first, if LingerTime is 0 (default), the system will attempt to send pending data for a connection until the default IP protocol timeout expires.

In the second scenario, LingerTime is a positive value, the system will attempt to send pending data until the specified 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 is 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 (by a client acknowledgment, for example), setting this property to False might be the appropriate course of action.

LingerTime is the time, in seconds, to leave the socket connection linger. This value is 0 by default, which means it will use the default IP protocol timeout.

The LocalHost 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 multi-homed 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 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 multi-homed hosts (machines with more than one IP interface).

This 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; setting is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.

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 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 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 is 256 bytes. The default value is 2048 bytes. The maximum value is 65536 bytes.

This 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.

If set to a positive value, this setting defines the length of data records to be received. The component will accumulate data until RecordLength is reached and only then fire the DataIn event with data of length RecordLength. This allows data to be received as records of known length. This value can be changed at any time, including within the DataIn event.

The default value is 0, meaning this setting is not used.

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 and KeepAliveInterval to configure the timing of the keep-alive packets.

Note: This value is not applicable in Java.

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:

This 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. In order to keep streams open after the transfer of data, set this to False. the default value is True.

When true, the socket will send all data that is ready to send at once. When false, the socket will send smaller buffered packets of data at small intervals. This is known as the Nagle algorithm.

By default, this config is set to false.

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.

This minimum cipher strength 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.

Please note that this setting contains the minimum cipher strength requested from the security library. The actual cipher strength used for the connection is shown by the SSLStatus event.

Use this 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 is currently not supported. This functionality is instead made available through the OpenSSLCipherList config setting.

Used to enable/disable the supported security protocols.

Not all supported protocols are enabled by default (the value of this setting is 4032). If you want more granular control over the enabled protocols, you can set this property to the binary 'OR' of one or more of the following values:

When the provider is OpenSSL, SSLCipherStrength is currently not supported. This functionality is instead made available through the OpenSSLCipherList config setting.

TLS 1.1 and TLS1.2 support are only available starting with Windows 7.

Change this setting to use security providers other than the system default.

Use this setting with caution. Disabling SSL security or pointing to the wrong provider could potentially cause serious security vulnerabilities in your application.

The special value "*" (default) picks the default SSL provider defined in the system.

Note: On Windows systems, the default SSL Provider is "Microsoft Unified Security Protocol Provider" and cannot be changed.

The following flags are defined (specified in hexadecimal notation). They can be or-ed together to exclude multiple conditions:

This functionality is currently not available in Java or when the provider is OpenSSL.

The enabled 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 is set to any other value, only the specified cipher suites will be considered.

Multiple cipher suites are separated by semicolons.

Example values when UseManagedSecurityAPI is False (default):

obj.config("SSLEnabledCipherSuites=*");
obj.config("SSLEnabledCipherSuites=CALG_AES_256");
obj.config("SSLEnabledCipherSuites=CALG_AES_256;CALG_3DES");

• 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

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_DH_ANON_WITH_AES_128_CBC_SHA");

• TLS_DH_ANON_EXPORT_WITH_DES40_CBC_SHA
• TLS_DH_ANON_WITH_3DES_EDE_CBC_SHA
• TLS_DH_ANON_WITH_AES_128_CBC_SHA
• TLS_DH_ANON_WITH_AES_128_CBC_SHA256
• TLS_DH_ANON_WITH_AES_256_CBC_SHA
• TLS_DH_ANON_WITH_AES_256_CBC_SHA256
• TLS_DH_ANON_WITH_DES_CBC_SHA
• TLS_DH_ANON_WITH_RC4_128_MD5
• TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA
• TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
• TLS_DHE_DSS_WITH_AES_128_CBC_SHA
• TLS_DHE_DSS_WITH_AES_128_CBC_SHA256
• TLS_DHE_DSS_WITH_AES_256_CBC_SHA
• TLS_DHE_DSS_WITH_AES_256_CBC_SHA256
• TLS_DHE_DSS_WITH_DES_CBC_SHA
• TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA
• TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_DHE_RSA_WITH_AES_128_CBC_SHA
• TLS_DHE_RSA_WITH_AES_128_CBC_SHA256
• TLS_DHE_RSA_WITH_AES_256_CBC_SHA
• TLS_DHE_RSA_WITH_AES_256_CBC_SHA256
• TLS_DHE_RSA_WITH_DES_CBC_SHA
• TLS_RSA_EXPORT_WITH_DES40_CBC_SHA
• TLS_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_RSA_WITH_AES_128_CBC_SHA
• TLS_RSA_WITH_AES_128_CBC_SHA256
• TLS_RSA_WITH_AES_256_CBC_SHA
• TLS_RSA_WITH_AES_256_CBC_SHA256
• TLS_RSA_WITH_DES_CBC_SHA
• TLS_RSA_WITH_RC4_128_MD5
• TLS_RSA_WITH_RC4_128_SHA

SSLEnabledCipherSuites is used together with SSLCipherStrength.

Note: This configuration setting is available only in .NET and Java.

If AbsoluteTimeout is set to True, any method which does not complete within Timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for UDP ports.

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).

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 receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

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.

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. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

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.

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 to false will ensure that the component does not attempt to process external events.

If set to True, when the component creates a thread the thread's IsBackground property will be explicitly set to True. By default this setting is False.

By default the component will use the system security libraries to perform cryptographic functions. This means 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 to True tells the component to use the internal managed implementation instead of using the system's security API.

Note that when this value is set the product's system dll is no longer required as a reference, as all unmanaged code is stored in this file.