Only alert if there’s actually a problem that is actionable. Please don’t throw email alerts at me if there’s nothing for me to do. Don’t be the boy who cried wolf. You probably already have an email rule that ignores alerts you don’t care about. Don’t make more spam.
Only alert if the problem is critical. In addition to my #1 requirement that it be actionable, I should have to act now. Email alerts are a cry for help, and aren’t appropriate for every problem. For lower-priority problems, I prefer digest reports, where I can set aside time in my day to work on many lower-priority issues and take care of them all at once.
I cannot agree enough with the cited section—this is so important for alerts, but something we tend not to think about. That’s why I have tens of thousands of unread alerts in my inbox tagged for auto-deletion (most of which alerts I didn’t create and don’t relate to me at all, but I can’t go breaking somebody else’s workflow).