Monitoring SMTP servers
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Monitoring SMTP servers
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 A TCP connection is established with the server IP address on port 25 (*) or a port number you select that represents your setup.
 Simple Failover waits for a "greeting".
 If the greeting begins with 220…, (*), then the SMTP server is considered functional.
With any other greeting, the server is considered non-functional.  The TCP connection is closed.
While performing above steps, Simple Failover may also encounter a communications error (winsock error), or that the TCP connection is unexpectedly closed by the remote server, or it may time out waiting for the TCP connection to be established or a response to be received. In any of these cases, the server is considered non-functional. Please note: It is not necessary to use Simple Failover for SMTP servers handling incoming e-mail. You can setup an MX-record for each of your SMTP servers in DNS. Other e-mail servers will then try each one of your SMTP servers in turn (according to the preference values in the MX-records) until a successful delivery is made. However, you may wish to use Simple Failover for SMTP servers handling outgoing e-mail. E-mail client software (such as Outlook) does not use MX-records. For details on the SMTP protocol, please see RFC821. This and other RFCs can be obtained from http://www.rfc-editor.org/rfcsearch.html. (*) Alternate port number can be specified in the Port field. Alternate status codes can be specified in the Advanced Server Set Properties dialog. |
