It's kinda difficult to help with this, without knowing what the A-Plus server is seeing.

An unsanitised copy of the bounce message would probably show the problem.

Does it definitely show the correct email address of a user for which A-Plus has a mailbox?

Can you reproduce the problem telnetting to the A-Plus MX server on port 25?

http://www.yuki-onna.co.uk/email/smtp.html 

http://www.simplescripts.de/smtp-check-port-25-telnet-command.htm

Stroller

On 10 Apr 2008, at 19:44, Jason Messerschmitt wrote:

I guess I'll dip my toes in here and admit that I can't figure this out.

Synopsis:  I've setup Postfix to be a mail out only smtp server. I just want it for our Joomla based web pages and our helpdesk to be able to mail to users from the local server. The problem is this: I can mail to any domain (gmail, hotmail, yahoo, etc) without problem, but I can't receive mail directly through our A-plus based mail (the worst!). What happens is that A-plus' server rejects the user as unkown even though I know it is correct. What really gets my goat is that after that message is returned to my server it is then delivered to the A-plus server and thusly shows up in my webmail and email client. Below are my configs.