MX Control
Properties Methods Events Configuration Settings Errors
The MX component enables querying of mail exchange (MX) records from a Domain Name Server (DNS). That is, it will find out the name(s) of the mail server(s) accepting email for a given email address or domain.
Syntax
MX
Remarks
The control will attempt to automatically determine the name of a DNS server from the system settings or from the value of the DNSServer property.
The control operates in synchronous or asynchronous mode, depending on the value of the Timeout property. Calling the Resolve method makes the control query the DNSServer. The Response event is fired for each server that handles mail for the email address. The control will fill out the MailServer property with the most preferred mail server and the Status property to "Ok" or an error message.
The RequestId property may be used to identify requests and is used in the Response event. The user may set its value before sending out requests, and then match the responses to the request using the RequestId parameter in the Response event.
Property List
The following is the full list of the properties of the control with short descriptions. Click on the links for further details.
| DNSPort | The port where the DNS server is listening. |
| DNSServer | The address of the DNS server. |
| Idle | The current status of the component. |
| LocalHost | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
| MailServer | Mail server with lowest precedence value (lowest cost to reach). |
| RequestId | Identifies each request. |
| Status | Status of the request is empty while in progress, 'OK' or error message upon completion. |
| Timeout | A timeout for the component. |
Method List
The following is the full list of the methods of the control with short descriptions. Click on the links for further details.
| Config | Sets or retrieves a configuration setting . |
| DoEvents | Processes events from the internal message queue. |
| Interrupt | Interrupt the current method. |
| Resolve | Resolves an email address. |
Event List
The following is the full list of the events fired by the control with short descriptions. Click on the links for further details.
| Error | Information about errors during data delivery. |
| Response | Fired for each MailServer accepting email for the domain. |
Configuration Settings
The following is a list of configuration settings for the control with short descriptions. Click on the links for further details.
| CaptureIPPacketInfo | Used to capture the packet information. |
| DestinationAddress | Used to get the destination address from the packet information. |
| DontFragment | Used to set the Don't Fragment flag of outgoing packets. |
| LocalHost | The name of the local host through which connections are initiated or accepted. |
| LocalPort | The TCP port in the local host where the component binds. |
| MaxPacketSize | The maximum length of the packets that can be received. |
| ShareLocalPort | If set to True, allows more than one instance of the component to be active on the same local port. |
| UseConnection | Determines whether to use a connected socket. |
| QOSDSCPValue | Used to specify an arbitrary QOS/DSCP setting (optional). |
| QOSTrafficType | Used to specify QOS/DSCP settings (optional). |
| UseIPv6 | Whether or not to use IPv6. |
| AbsoluteTimeout | Determines whether timeouts are inactivity timeouts or absolute timeouts. |
| FirewallData | Used to send extra data to the firewall. |
| InBufferSize | The size in bytes of the incoming queue of the socket. |
| OutBufferSize | The size in bytes of the outgoing queue of the socket. |
| CodePage | The system code page used for Unicode to Multibyte translations. |