We have these in M&F. You do need to be very careful about how they are set up, in particular being able to aggregate several "notices" into a single email. It is common that overnight my M&F notifications generate 200 or more emails.
M&F notifies on people in sight, which I find silly and non-relatable to BM... notices on messages, battles, big actions (someone issued a duel) or big outcomes (duel lost!)... I suppose I should classify what I think could be useful.
