We switched over to Zimbra recently, (zcs-4.5.8_GA_1394 on Ubuntu 6.0.6, single-server) and had several problems with non-obvious configuration settings, which we fixed after digging through forums.
However for one fix we used, I am sure there is a better alternative.
Currently, every time we create a new user in our main domain (different from the default domain), we have to force it use the local server for receiving mails off the queue via LMTP, via the following LDAP configuration:
zmprov ma firstname.lastname@example.org zimbraMailTransport lmtp:192.168.0.250:7025
...where 192.168.0.250 is the IP of the server.
Obviously the downside of this approach is that we have to perform this command-line step every time we create a new user.
I am sure there must be a better way, either:
a) Setting a global or domain-level setting which applies to all users
b) Setting a template value which all new users take upon creation.
Unfortunately we could not find such a value and the Zimbra documentation is especially unclear on what are the correct values you can put in the several LMTP-related fields you can set via the webadmin UI. For instance, reading through the forums, some fields appear to require hostname, others FQDN, others IP address, and others IP address plus port.
If anyone could suggest a better method, or simply point me at an LDAP schema reference which explains the available options, that would be much appreciated.