Mailman stops responding or otherwise needs to restart

[Matt]

We have a small number of users on our internal platform. One of them uses a mailing list to send e-mail out and frequently calls about the e-mails not being sent out. I've dug around and noticed that if I restart mailman service the queued mail is then sent out. Not sure where to look for why this keeps happening ever few weeks. It could also be related to ongoing bruteforce attacks on our server though most of the attempts appear to be in vein.

[Mark Sapiro (msapiro)]

Start by checking that all the qrunners are running, particularly IncomingRunner and OutgoingRunner. Check for a locked list. Check Mailman's logs, particularly 'error' and 'qrunner' for errors. See ttems 6.2, 7 and 8 at https://wiki.list.org/x/4030723