I've been struggling with what seems like an SMTP problem for a few days now (I'm stubborn that way and like to resolve things myself...), but now am turning to you for help (finally came to my senses).
I am running a single server Zimbra install on Ubuntu 6.06 LTS server (non-LAMP install) within VMWare on Windows XP host. The install and configuration went fine after reading a few guides on various sites, including the Zimbra forums (see here for main install and here for split DNS config using bind9).
Overall, the install went well. I can send email between users on the server, but not send/receive externally. All messages end up as deferred due to connection time-outs.
I have tried several things, including several uninstall/install cycles, but to no avail. I also verified that the A and MX records are correct, etc.
I believe the problem is in the SMTP setup, as there in no response from external telnet session into the server on port 25 (internally it's fine).
I tried the various diagnostic methods found on the wiki and other places, but don't seem to be able to identify the specific problem.
Here is what's in the /var/log/zimbra.log file:
I'm hoping you can help me...
Jan 22 00:40:39 mail postfix/qmgr: 0343CCB587: from=<email@example.com>, size=1143, nrcpt=1 (queue active)
Jan 22 00:41:09 mail postfix/smtp: connect to krauze.net[220.127.116.11]: Connection timed out (port 25)
Jan 22 00:41:09 mail postfix/smtp: 0343CCB587: to=<firstname.lastname@example.org>, relay=none, delay=269, delays=239/0.08/30/0, dsn=4.4.1, status=deferred (connect to krauze.net[18.104.22.168]: Connection timed out)