Mostly email, but can be letter too ( did you get AOR ) always keep on top of ur file since some of us missed the communication and 1 user even got rejected
Check the timeline ( see sig ) - and you can get some idea but normally its about 7 months + after file xfer, Kandel ( user here ) is still waiting since her file xfer in Sept, 2012 - has dependants but that's not the factor for delay
There is another user who still haven't received but I recommend to order GCMS notes as there is lot can go wrong, like mine for eg went to the wrong email - you can read past posts as it was hell of a time.
Some folks try to get info from MP and are given either a proper or generic response