I'm running postfix on a debian lenny system. sending mail in general works without any problems. however some recipent mail systems return an error and I can't get a clue what is causing the problem. So far I suspect that this is either postfix setup itself or the reverse dns resolution.
The mail server is running on a virtual server from my service provider.
running the command hostname is returning my.domain however running host <ip-address> is returning some alias from the virtual server system. now i'm not quite sure if that is causing my problem????
The mail system
<recipient-mail>: host mx0.recipient.domain[xxx.xxx.xxx.xxx] refused to talk to me:
550 Forged HELO: you are not my.domain
Reporting-MTA: dns; my.domain
X-Postfix-Queue-ID: 6A1135B08002
X-Postfix-Sender: rfc822; name@my.domain
Arrival-Date: Tue, 13 Apr 2010 17:50:36 +0200 (CEST)
Final-Recipient: rfc822; recipient-mail
Action: failed
Status: 5.0.0
Remote-MTA: dns; mx0.recipient.domain
Diagnostic-Code: smtp; 550 Forged HELO: you are not my.domain
Best Answer
This might be an issue with your HELO/Reverse DNS. Take this Email Server Test and follow its recommendations.