Hi,
We are experiencing rather frequent mail deferrals because of a
milter-related malfunction:
Oct 22 08:48:14 mailhost3 postfix/smtpd[723]: 23C7F8FF16:
client=xxx.xxx[1.2.3.4]
Oct 22 08:48:14 mailhost3 postfix/cleanup[1415]: 23C7F8FF16: message-id=<xxxx>
Oct 22 09:18:16 mailhost3 postfix/cleanup[1415]: warning: milter
inet:localhost:12337: can't read SMFIC_HEADER reply packet header: No such file
or directory
Oct 22 09:18:16 mailhost3 postfix/cleanup[1415]: 23C7F8FF16: milter-reject:
END-OF-MESSAGE from xxx.xxx[1.2.3.4]: 4.7.1 Service unavailable - try again
later; from=<...> to=<...> proto=ESMTP helo=<...>
We use only the amavisd-milter milter (together with amavisd-new). Also,
we have a few policy daemons (in particular, apparently a lot of
policy-spf.pl processes).
What I find interesting is that the error comes after 30 minutes. The
relevant timeouts are however as follows:
daemon_timeout = 18000s
ipc_timeout = 3600s
milter_command_timeout = 30s
milter_connect_timeout = 30s
milter_content_timeout = 300s
smtpd_policy_service_timeout = 300s
smtpd_timeout = ${stress?30}${stress:180}
If this is a problem with the milter, shouldn't Postfix realize that the
timeout has expired before (i.e. after 30 or 300 seconds)? Also,
shouldn't the whole session be interrupted after 180 seconds?
Any idea about what could be causing this? My theory is the following:
- A policy daemon blocks the whole SMTP transaction and finally times out.
- Postfix doesn't timeout and proceeds with the email, even though the
connection is 30 minutes old.
- Postfix tries to speak again with the milter, which has however
disconnected in the mean time.
Thanks for any help,
David
