They are just the warnings for when accounts are "approaching" the limits. They are messages in the message system with an email also going out containing a link to the message system. There actually is no notification for suspensions, manual or automatic... might be something to add.
One of our resellers got upset this morning because DA suspended his account (bandwidth over quota). He seems to think it was our fault and that we should "fix the problem with the server". He seems to have forgotten that he went over limit.......
However, is the suspension notification going to be added?
I was rather surprised to find out it wasn't already in.