Split Domain - How to make primary aware of secondary?

[quietas]

Quote from the Split Domain instructions:

# The primary MTA must
* be aware of, and accept mail for, all accounts on the domain
* reject on RCPT TO: those accounts that do not exist in either system
* forward mail to the secondary MTA for users hosted there.

Primary Mail Server Details:

• Debian 4
• Exim
• Courier-Imap
• MailScanner
• Iptables
• Webmin
• On DMZ behind firewall

Secondary Zimbra Test Server:

• Ubuntu 7.10 (6.06 will not work do to Grub issue on this test box)
• P4 2.0ghz, 1.5gb RAM, 160gb HD, CD-ROM
• Zimbra NE 5.05 60 trial (downloaded 5/1/08)
• Also on DMZ

Network Layout:

• Internet via ISP router -> WAN (Sonicwall firewall appliance)
• DMZ -> switch -> debian and zimbra (direct internet IP's)
• LAN -> 192.168.xxx.xxx

Question:
How do I make the primary mailserver aware of the new Zimbra secondary mail server? What do I need to do so that it knows what users I move or better yet, new users I create, on the new Zimbra system?

Any help would be appreciated. I think I have Zimbra set up according to the split domain instructions, but I'm not sure.

~ Culley

[quietas]

Quick update. I have Zimbra installed and I can email out using my main email as a relay. I created a new account on the new server and tested with this.

How can I get the new secondary server to recieve emails that are sent to the existing primary?

[phoenix]

How can I get the new secondary server to receive emails that are sent to the existing primary?

It tells you what you need to do in the wiki article , if you want to still get mail into your original server first then this quote is important:

Deployment Scenario A: User Migration to Zimbra

We are often asked how to configure the Zimbra Collaboration Suite so that some accounts are moved/migrated to Zimbra but other accounts continue to live on the existing mail system, in what would be a Split domain. This is possible if your mail system offers some of the mail routing features that Zimbra offers.

Does your current mail server have the facility to route mail? If it doesn't then follow the instructions in Section B of the wiki article, that has everything you need.

[quietas]

Hmm, I am seeing plenty of info regarding Postfix and Split Domains, but nothing for those of using Exim (not my choice, old server).

Anyone have any info?

[mmorse]

Documentation for exim

[quietas]

If I am only setting up a relatively small number of test users (under 20), could I just create an alias?

user.test: user.test@mailtest.domain.com

Could that work? I know I have a few emails where this works to have a local email address which the mail goes to a remote outside address.

[quietas]

It seems that this will not work.