Honestly I'm baffled. I have no idea what's going wrong. The last thing I can think of is I have another mail server on a different domain running on the same gateway. Could that box be hogging port 25 and no allowing traffic to my other domain?

Did you verify the settings, router, forwarding, firewall?
Is the mail daemon running?
Please post the output from
on the server
Then
from another computer on your network
and finally
From outside your network

Kind regards

1st suggestion I can connect. 2nd and 3rd I cannot. Error message on 2nd and 3rd is connection refused. I have checked everything, firewall, DNS, port forwarding is all correct. Thanks.

Did you changed the conf file as stated in
http://www.linuxquestions.org/questi...ml#post4303132

Kind regards

Yes I did that. Everything seems to be setup correctly. Maybe I should give a complete picture of my network. Here's what I have setup:

1 OS X Server as DNS/Web/Mail server setup for one domain
1 OS X Server as DHCP/slave DNS server

What I'm trying to now do is set up a Linux equivalent of that with:

1 CentOS Web Server/slave DNS
1 CentOS Server as DNS/Mail server

I'm doing this as training for myself. The OS X setup I've done just fine and it works correctly. The Linux one only the Web server and DNS is working correctly. The mail I cannot get running. The only thing I can think of at this point is there's something going on with having two domains running on one gateway. It seems unlikely but I cannot see why Postfix/Dovecot on the Linux servers will not work. Perhaps if I remove the OS X components of the setup?

Thanks for any insight/thoughts.