Backup mail server and spam filtering, Backup mail server and spam filtering

[Andy]

I have 2 servers - both running win 2003 and xmail 1.22
One of the servers acts as a backup by using custom domains and forwarding any mail received to the other "live" server. The live server has spamassassin 3.02 installed and filters incoming mail using Dario's xspamc

My problem is that the odd email is coming via the backup server rather than going directly to the live server (I can only assume that some some mail servers are not checking the preference order of the mx records correctly because I am not aware of the live server being unreachable at the time these messages are received) The issue really is that because the email comes from the backup server the checks made by spamassassin on the senders domain/ip are my backup servers address and not the originating senders domain/ip.

I don't think I can just put spamassassin and the filters on the backup server as the emails do not use domains/mailboxes.

Has anyone got any ideas ? I have almost eliminated spam for my users but there are the odd few that get through because of the above. Ideally I would only want the backup server to receive mail if the live server is uncontactable.

Thanks

Andy.

[hschneider]

Use a scheduled SmokePing or some similar tool to test if server #1 is alive. If not, launch the backup server : http://oss.oetiker.ch/smokeping/

This will force clients which do not care about your MX entries to use server #1.