I've been wanting to ask this question for close to 4 years now, but have always been to lazy to do so lol.. so here goes:

What is the algorithm for sending out email notifications on new messages in a subscribed thread? I've noticed varying inconsistencies in these messages being delivered. For example I might receive a new notification for each new message in a thread and then all of a sudden I don't receive any at all for the same thread. If you are logged in do the notifications stop?