I'm looking to migrate a Qmail server to Zimbra. I have Zimbra 6.0.6 up and running and it is accepting and delivering email for our domain (foo.com).

The new server (secondary) is zimbra.foo.com, the old server (primary) is mail.foo.com.

I'd like for Zimbra to accept email for both foo.com and zimbra.foo.com, but currently it only accepts foo.com. I get the following error when sending email both from the web interface as well as from other mail clients:

unknown user: "<username>"

Where <username> is a user account that is setup in zimbra and on the old mail server.

I've followed the steps in the Split Domain wiki page for the secondary domain setup to no avail.

What am I missing?