Shared Domains

[informatique]

I have the following scenario I'm unsure on how to setup :

My domain test.com as recipients on 2 mail servers totally independant from each other. The MX record point to an Ironport box who does some LDAP filtering and foward some recipients to a local exchange server and other recipient to my Ironport box.

Incoming mail to @test.com:
Internet > Ironport1 (LDAP Filtering) > Ironport2 > Exchange2.
Internet > Ironport1 (LDAP Filtering) > Exchange1

Outgoing mail to @test.com:
Exchange2 > Exchange2
Exchange2 > Ironport2 > Internet > Ironport1 > Exchange1

My problem seems to be with he outgoing mail. My Ironport2 is configured to accept mail @test.com and has a route configure to deliver test.com to Exchange2. When outgoing mail hit the ironport it seems to generate an NDR right away. Is this the expected behavior or should it be working and something is either wrong with my test or my configurations?

[steven_geerts]

Hello,

If I read your message correctly your Second Ironport does not have knowledge of what recipients reside on Exchange1 or Exchange2. It simply routes all mail to @test.com to Exchange2.

This would explain your NDR's, since this means a mail to @test.com from Exchange2 will be routed back directly to Exchange2.

There are (at least) two possible solutions for this:
1) Give Ironport2 knowledge about where to route mail to (Ironport1 or Exchange2).

2) Create a policy that forwards all mail received from Exchange2, targeted to @test.com to Ironport1. (If you want, I can assist you in creating this policy)

Good Luck!

Steven