Header problems from AWS MX server

[WolfyPDX]

I've recently moved our Zimbra server and our sendmail-based MX server to Amazon's EC2 service. Everything is working fine except for one minor glitch that really doesn't hurt anything, but is simply an annoyance (at least for now it is only an annoyance).

If mail is generated on the MX server (say, for instance, via cron), it gets sent to the Zimbra server with headers as follows:

From: somebody@mx.example.com
To: me@mx.example.com

which is fine - that's the way I want the headers to look. However, when it arrives in my Zimbra mailbox, the headers have been rewritten as follows:

From: somebody@ec2-##-##-##-##.compute-1.amazonaws.com
To: me@ec2-##-##-##-##.compute-1.amazonaws.com

which is not what I want. I've tracked this down as something that is occurring on the Zimbra server - if I telnet in to port 25 and send the headers I want, they still end up being rewritten somewhere in the Zimbra system.

ec2-##-##-##-##.compute-1.amazonaws.com is the "real" name for our MX server, with mx.example.com being a CNAME that points to that name. Reverse DNS returns mx.example.com

Any ideas about how to prevent Zimbra from rewriting these headers?

TIA

PS. The header says I'm using release 5.0.18 - we're actually using zcs-6.0.14_GA_2928.RHEL5_64.20110802123437 (not sure how to change the header)

[phoenix]

Originally Posted by WolfyPDX

ec2-##-##-##-##.compute-1.amazonaws.com is the "real" name for our MX server, with mx.example.com being a CNAME that points to that name. Reverse DNS returns mx.example.com

Any ideas about how to prevent Zimbra from rewriting these headers?

A CNAME should never be used to point to a mail server, it can cause problems (including lost mail). In these circumstances, however, it would appear the system is working correctly - Zimbra (Postfix) does an MX lookup for your other server and does not use the CNAME.

Originally Posted by WolfyPDX

PS. The header says I'm using release 5.0.18 - we're actually using zcs-6.0.14_GA_2928.RHEL5_64.20110802123437 (not sure how to change the header)

It went walkabout during a recent software upgrade, you can modify it here: www.zimbra.com/forums/profile.php?do=editprofile