SharePoint Email Alerts being sent sporadically or not at all.
Alerts from lists and sites were being sent sporadically or not at all. When i looked into the Timer Job Status page in central admin, i noticed that the set of jobs on 1 of our Load Balanced Web Front Ends were in bad states. Specifically, 2 of them were stuck in Initializing, and 2 of them were stuck in Failed.
We restarted the Windows SharePoint Services Timer ( SPTimerV3 ) in Services Console, and this resolved the problem.