Email Delivery Issues

[ManovrareSoft]

Email Delivery Issues - Ignoring Custom MX?

First, I don't know if it matters or not but this install is over at 1and1. We are using 10.4.4 Update #23, last updated at Mar 25, 2012 03:30 AM.

Background Information:
I have two separate domains we will call them: abc.com and xyz.com.
abc.com plesk for email management
xyz.com has mail directed to external (ms exchange) mail servers.
xyz.com has a custom mail.xyz.com A record that points to a different IP address.

Problem:
Our php application on abc.com sends emails out based on client interactions.
When abc.com sends email to xyz.com email's are not getting delivered.... but if abc.com sends emails to @gmail.com then it is delivered.
Usually it will say (when delivered to external email addresses) "replyto@abc.com via server.onlinehome.com"
Also... email's NOT originating from abc.com are arriving fine at xyz.com

Possible Issues:
I feel like it is a very real possibility that when abc.com sends email to xyz.com the server is somehow ignoring the fact that xyz.com has mx records and delivery fails.

Services Running related to Mail
SMTP Server (Postfix)
Plesk milter (Postfix)
IMAP/POP3 Server (Courier-IMAP)

Where would I find the mail log? I know it is under a "psa" folder some where but have been unable to find it yet.

 

[ManovrareSoft]

Additional Information

It appears that whether or not they are in different subscriptions does not matter. And it also does not matter if it is sent from a PHP application, I used horde to test sending and receiving on different email addresses from withing the subscription and all worked fine except for those with custom MX records (and custom mail.domain.com records, which are pointed to different IPs)

I can try to send email to xyz.com from any of the other domains and it never makes it to our exchange server used at xyz.com.

Email from one domain to another neither having custom MX records works fine.

Somehow plesk or the mail service is just simply trying to deliver the mail to the qmail program but it should be trying to deliver the mail to the custom MX servers listed in Plesk and 1and1's DNS (1and1 overrides Plesk, but I did it in both locations just in case)

-OR-

It is trying to deliver mail directly to the mail.xyz.com which is a custom A record not related to the Exchange Server. (we use it for a different service and is pointed to a non-mail server)


This has to be some kind of bug that can be worked around, like if mail.xyz.com HAS to point to the server IP address for it to honor the MX records, then maybe we can change the configuration to look at maildelivery.xyz.com because we can't change mail.xyz.com to something else at this time (unless of course it is somehow required).

 

[ManovrareSoft]

I found this, it almost exactly is my issue:

http://forum.parallels.com/showthread.php?t=70201

Problem is, in my /var/qmail directory, there is only the folders "mailnames" and "popuser". "mailnames" had the xyz domain in it and I deleted the folder, but to no avail, it is still trying to deliver the mail locally I think