Some Mailman list mail delayed (resolved)
Due to a problem with the Mailman list management software, some Mailman list mail sent yesterday (December 2) and this morning (December 3) was delayed (although most was delivered normally).
We’ve resolved this. All delayed list mail has been delivered, although some messages may have arrived out of order due to the delay.
The problem was caused by a corrupted list message causing one of several Mailman “qrunner” server processes to “hang”, which we haven’t seen happen before (and we’ve used Mailman for over 13 years). Although we have several monitoring systems in place to detect Mailman problems (including slow delivery), this problem didn’t affect any of the test messages that system sends, so the alarms weren’t triggered.
We sincerely apologize to anyone affected by this problem. Like you, we expect prompt mail delivery in all cases. To ensure this doesn’t recur, we’re adding additional Mailman software monitoring that will immediately detect and correct this problem if it happens again.