I think I have a fairly easy question this time. I have my MTA on one server and my Mailbox on another. I'm able to send mail to other domains just fine, however if I send mail to my domain it all ends up in the deferred queue. They all say the same thing, and the names have been changed to protect the innocent.
"Reason: delivery temporarily suspended: connect to mailbox.example.com[192.168.1.2]: connection refused"
So my question is simple. What port is this occuring on so that I can open it?
I tried looking in /opt/zimbra/log on the MTA server for more detail but this is all I found.