On 4/22/2011 10:40 AM, Shields, Rusty (IMS) wrote:
Thanks to those who responded to my earlier email.
I'll restate my problem and post the output from postfinger below that.
Our postfix server has recently started reporting bounces for emails that are
being successfully delivered. These are all for email addresses that are all
within our domain, with one server acting as a relay for multiple servers
within our organization. Also, there's no real pattern that I can see. Within a
short timeframe (10-15 minutes), similar emails from the same source to the
same users have alternately been recorded with status of sent, bounced and
sent. Postfix has been running in this fashion on this server for quite a long
time, but these false bounce reports just started appearing about a week ago.
The bounced emails are recorded like this in the log:
Apr 14 17:22:57 tilapia postfix/smtp[19383]: 8F27A27954:
to=<hama...@imsweb.com>, relay=mailrelay.imsweb.com[204.132.58.6], delay=0,
status=bounced (host mailrelay.imsweb.com[204.132.58.6] said: 554 Format restriction
violation. Email Session ID: {4DA765B1-6-6565EC3F-FFFF} (in reply to end of DATA
command))
The 554 response code sent by the remote server is a firm
"message not accepted" response according to the SMTP protocol
standards.
The remote server signals that it will not accept the message
and postfix should return it.
Apparently the remote server is badly broken and delivers the
mail anyway.
Postfix is just the messenger; don't blame postfix when the
other server falsely says "not accepted".
What do you want postfix to do when the remote server lies?
You can turn on the postfix soft_bounce feature; this will
result in either multiple deliveries of the same message, or
in the case of mail that the remote server really won't
accept, will result in mail stuck in the postfix queue. This
covers up the problem.
You can hack postfix to pretend that mail is successfully
delivered despite what the other server says; this will result
in lost mail in cases where the remote server really won't
accept the mail and it should be returned. This ignores the
problem.
What kind of software is running on the other server? Any
recent upgrades or config changes to that software -- maybe
some anti-spam controls updated? The remote server is where
the problem is, and where it should be fixed.
-- Noel Jones
