At least my mail is delivered by a harmless old guy.

Seriously though, I love seeing that little mail icon pop up in game. It means either someone accepted my trade, or maybe it's something good from my guild buddy's. Maybe it's even a declaration of war on a rival guild.
Often times even if I don't have much time to play I will log into Saga just to assign another task to my peasants and read any mail I may have.