iMark writes:
From time to time Microsoft will spit the dummy and start blocking mail from the lists.
We're all familiar with this....
This will last a day or two, but in the meantime bounce counts get cranked up which can send some lists over the edge and start disabling/removing subscribers.
Only the first permanent failed delivery in a calendar day is counted. Both temporary (status 4xx) failures and additional permanent (5xx) failures are logged and update the "most recent bounce" timestamp, but do not increment the bounce count. If the threshold is set to "3" (days) it will be at least 72 hours before a "clean" subscription is disabled.
The process is implemented in model/bounce.py:BounceProcessor.process_event. (The header comment for that section of code is sloppy, read the code.)
The disable delivery threshold and the interval after which bounce info is considered stale is configured per-list in Postorius.
-- GNU Mailman consultant (installation, migration, customization) Sirius Open Source https://www.siriusopensource.com/ Software systems consulting in Europe, North America, and Japan