I am having the same problem, unfortunately the problem continues. The web server module seems to work OK and I can send e-mail but not receive them. It is possible that our hardware firewall could be provoking this? I am using Fedora Core 2 and followed as close as possible the Fedora Core 3 perfect setup (just changed accordingly, for example the reps). My pop daemon is ipop3.
My mail is bounced back like this (the local name of the machine is LinuxServer, and it is going to host many domains, currently it has only one domain which I dubbed here as mydomain.com):
This is the Postfix program at host LinuxServer.
I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.
For further assistance, please send mail to <postmaster>
If you do so, please include this problem report. You can
delete your own text from the message returned below.
The Postfix program
[linuxserver.linuxserver]: Name or service not known
Final-Recipient: rfc822; mydomain.com_postmaster@LinuxServer.LinuxServer
Diagnostic-Code: X-Postfix; [linuxserver.linuxserver]: Name or service not