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.
It is not silly when things happen every hour. Spotting an enemy and getting a email could be the difference between acting in time and comming online a few hours later and not having time. Course that is one the things in the game that people struggle with, the speed. It is great when you are at peace or part of an active realm. Not so great when your enemy is far more active then you.