Dual platform environment

[jareep]

We are currently in the process of migrating from sendmail to Zimbra. We have MX records setup for mail.domain.com and mail02.domain.com. The original server is mail.domain.com and mail02.domain.com is the zimbra server. We have about 75 users on the old sendmail server and 3 users on Zimbra. Our architecture is currently setup with all mail coming into mail.domain.com and then if its one of the 3 Zimbra users it forwards to the Zimbra server.

The problem is we setup zimbra to be @mail02.domain.com and the original is @domain.com. Whats the best way to migrate from @mail02.domain.com while still allowing mail to be received at both places depending on whether the user exists or not? Basically both servers (sendmail and Zimbra) need to accept @domain.com and have the mail go to the appropriate place.

Sendmail is running on Fedora Core 5 and Zimbra is running on RHEL4 for reference. Any help would be appreciated.

[jareep]

Found this.

http://wiki.zimbra.com/index.php?title=Split_Domain

[3RiversTechAdmin]

Hey Jareep,

This is how I did it:

A is the old sever with send mail
B is the new server

Added a .forward file to all users on A that are moving to B, I had it save a copy locally and forward to B

setup A as B's relay host and disabled DNS lookups
setup B to accept all mail at my domain, thus any user it does not have an account on B will be forwarded to A because it is the relay host

Let me know if you have questions on specifics, I found everything i needed on google and the wiki.

[jareep]

I see what you mean, but I ran into a small mail routing problem that I feel I "hacked" around. There's probably a more elegant and correct solution.

Zimbra: mail02.mydomain.com
Sendmail: mail.mydomain.com

MX-1 mail02.mydomain.com
MX-2 mail.mydomain.com (and this can probably be removed)

User1@mydomain.com = sendmail user
User2@mydomain.com = Zimbra user

user2 has a .forward file in sendmail that is User2@mail02.mydomain.com. Then in Zimbra I created mail02.mydomain.com as another Zimbra domain and added a User2@mail02.mydomain.com alias for User2@mydomain.com. The reason was that sendmail users were not able to send mail to the Zimbra users.

I didn't want to delete the sendmail user accounts and thats what was causing the problem. Would it be possible to have the .forward file say: User2@mydomain.com? Seemed to me that sendmail would try sending to itself and it might create a routing loop. Ideas on that?

[3RiversTechAdmin]

Hey Jareep,

First of all, I am not worrying about MX records untill the actual switch of my systems. For now all mail to B comes from A.

As for loops in the .forward file, I can help you with that.
here is the format for the .forward, the slash in front of the local username keeps it from becoming a loop.

\sendmailUsername, newMailUsername@newHostname.domain.com

Assuming of course your zimbra box has a fully q'd hostname