You've helped me with some other issues today. I think I'm almost setup. I'm having a similar issue to eXtremeSG except I think I know what my issue is and I don't remember how to resolve this with postfix and maybe you can help.
when I run host `hostname` it returns with my hostname as:
myserver.domain.com has address 18.104.22.168
of course, myserver.domain and the address are replaced with my real name and address. The problem is that this server is running in a vm in my network that doesn't have a static IP address nat'd to it. INstead, I'm port forwarding on my home router to this internal vm that's on 192.168.200.11/24. I remember in the past, when I've setup postfix on an internal server, I had to tell it somehow to not do a dns lookup on my domain name when delivering mail and instead, use a virtuals table or something like that-- which basically told postfix that anything bound for @somedomain.com should go to some IP (namely 192.168.200.11, instead of the outside IP).
Currently I have a ton of incoming mail stuck in postfix, when I do postqueue -p from zimbra's user. When I look in the /var/log/maillog and postqueue -p it looks like all these messages are trying to be delivered to to my outside IP address of my router instead of the internal IP of 192.168.200.11.
Here is one such result of postqueue -p:
When I tail maillog, here is one of the results:
Feb 13 16:37:52 myserver sm-msp-queue: k1C2VVTn002294: to=postmaster, delay=1+18:59:59, xdelay=00:00:00, mailer=relay, pri=3913803, relay=[127.0.0.1], dsn=4.0.0, stat=Deferred: Connection timed out with [127.0.0.1]
Mail internally can go out, mail coming into postfix comes in and seems to get stuck (I'm thinking trying to go to amavis or clam or spamassasin or somewhere that should be internal to this box) trying to leave postfix for another internal destination.
Might you have any suggestions?
UPDATE: actually, here is a post that seems to be exactly my issue:
Mail not getting to mail boxes
Installed OK - Can send but not recieve email
but it looks I feel the same way about KevinH's resolution to put up an internal dns server. I know that there is some postfix .db file that you can create to adjust the behavior of postfix only for that domain... I'll keep searching on postfix sites and here, but if anyone knows what this file is, please let me know.