[cobalt-users] MX Records and failover servers

["Jay Fesco" <jay@xxxxxxxxxxxxxxxxxx>]

Hi, all...

I have a setup question that I'd like to not have to 'what if' on our live server.  If anyone has set up something similar I'd greatly appreciate your experience.

Machine is a Raq4r.
We run Sendmail for most of our web clients, and the setup for them is very straightforward: A record for mail.domain.com, MX record pointing at it, Email Server listed as 'domain.com' in the vsite setup.  Works well, no problem.

For a couple of clients, and especially for our own internal mail, we direct mail to an Exchange server at a 'foreign' IP address (outside the cobalt).  No worries again, A record pointing to the Exchange server, MX points to that A record, No email server listed in the Vsite setup.

Here's the issue - I want to set up the Cobalt/sendmail as the Low Priority (failover) mail server for the sites that use Exchange.  I have the A records set for mail.domain.com and mail2.domain.com, 2 MX records, one High Priority to mail. and one Low Priority to mail2.  

The question: Do I specify an email server in the Vsite setup?  I know from experience that if I just put mail.domain.com it starts intercepting mail and does not behave itself (does not allow mail to forward to the Exchange server).  Do I put mail2.domain.com or just leave it blank and allow BIND to handle it?

Thanks - let me know if I need to clarify.
Jay Fesco