Zimbra eval in parallel with existing mail server

[hmirsky]

We are attempting to evaluate Zimbra in parallel to our existing locally hosted production (sendmail) mail server. We do not want to disrupt the existing mail system while we evaluate Zimbra. After reading Zimbra's instructions for a "Split Domain" I plan to make the following change to our mail server. Can anyone comment on this approach or alternative? Thanks in advance!

Assume our current mailserver is fruit.example.com and the new server that will host ZCA is zmibra.example.com

On fruit.example.com:

1. Configure mailertable with this one line:
example.com esmtp:[fruit.example.com]:[zimbra.example.com]

2. Declare example.com as a virtuser_domain. In mc file add:
VIRTUSER_DOMAIN(`example.com')

3. Setup our virtusertable to handle the messages we want delivered
locally. Omitting an address will cause it to route to zimbra. Our
virtusertable will contain one line like the following for each email address to be kept on fruit:
local1@example.com local1@fruit.example.com

As fruit is already configured to handle mail for local1@local1.com, mail will go where we want. The mailertable entry will tell sendmail to route the messages that aren't handled by virtusertable (during rule set 0) to zimbra. The colons separating the hostnames in mailertable tell sendmail to use the entries in a MX fashion rather than round-robin.

[Krishopper]

I kind of find the split domain thing to be a pain in the butt, honestly.

If you're evaluating Zimbra, I would suggest the following:

1. Set up zimbra.example.com like you have. For the domain name within Zimbra, set it as "zimbra.example.com". Also set up MX records for zimbra.example.com to resolve to zimbra.example.com.

2. On fruit.example.com, for the accounts that you want to test Zimbra with, set up a forward to forward their email to user@zimbra.example.com.

3. In Zimbra, you can set each user up as user@zimbra.example.com, but set up a persona for each of them so that their mail address just appears as user@example.com when they send email out. That way replies will be directed through the main server once again.

This will ensure that emails go through the main server and can be stored in their mailbox (if you do a forward-and-copy type setup) if you decide that Zimbra isn't for you.

I really only ever use split-domain for migrations, to try to make it as transparent as possible.

Just my 2-cents.