Hi,
I’m running Mailman version 2.1.14 on an Ubuntu 12.04.5 LTS build, with Postfix MTA.
I recently noticed up to one hour delays between Postfix delivering messages to command "/var/lib/mailman/mail/mailman post [listname]", and Mailman effectively sending out the message to list members (as evidenced in Postfix log file, email headers, and Mailman logs).
The delays are consistent in that each posted message, to any list and with any number of subscriptions (between 1 and 250), is delayed by at least 20 minutes.
The Mailman "post" log file /var/log/mailman/post does not indicate the message being posted, until the message is finally being sent out up to one hour after the post.
However, the list’s archives, as well as the list’s digest.mbox file, DO contain the posted message immediately after posting, confirming that Mailman did instantly receive the message from Postfix.
Similarly, email notifications to admin (new list, memberships, …) suffer from the same delays.
There are no errors found in the qrunner, mischief, or smtp log files that give pointers as to why this happens.
The system is not under any load to speak of, and Postfix is running fine otherwise, delivering mail to local users and remote recipients instantly. The mail queue is virtually empty.
Would running separate, verbose instances of qrunner possibly give me any insight, and how should I go about this? Any input is appreciated.
Regards,
Nicolas