looks like mailman_queue_size regularly fires and recovers during UTC morning. note the threshold was raised in rOPUPaebf548041c4b so likely it needs some more tuning cc @dzahn
```
06:05 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 2 mailman queue(s) above 100
06:29 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:05 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:21 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:04 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:21 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:05 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:18 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:05 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:17 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:04 <icinga-wm_> PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:19 <icinga-wm_> RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:04 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:18 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
09:04 -icinga-wm:#wikimedia-operations- PROBLEM - mailman_queue_size on fermium is CRITICAL: CRITICAL: 1 mailman queue(s) above 100
09:26 -icinga-wm:#wikimedia-operations- RECOVERY - mailman_queue_size on fermium is OK: OK: mailman queues are below 100
```