I have this message over and over in the log on my personal Debian mailserver:
improper command pipelining after MAIL from mail.example.org[ip.ad.dr.es]
It started on November 10th, when I installed updates on the machine, upgrading postfix from 2.5.5-1.1 to 2.7.1-1~bpo50+1.
I grabbed a sniffer trace, where I found that Xymon is sending, in a single packet, a "mail" command followed by "quit". The server responds with the following because this is a violation of the strict RFC:
503 5.5.1 Error: send HELO/EHLO first
221 2.0.0 Bye
My postfix config has two places where it checks for unauthorized pipelining, one of which was not preceded by permit_mynetworks, so I fixed that, and it didn't help.
I am running the lenny-backports xymon package, version 4.3.0~beta2.dfsg-5~bpo50+1.
Can the test be re-engineered so that it follows proper SMTP protocol and waits for a server response between each command?
Thanks,
Shawn