I've noticed recently that some of my forum notification emails have been trapped as spam by my Windows Live Mail. This would suggest that potentially people have been marking them as spam and they are being blackholed by your email provider.
Oh and you'll only get one notification for a reply. If you don't ever read that particular thread again, many people can reply to it without any further notifications. Some forums will notify you of a reply each time, others will notify you even if you just log in and don't read the original thread. I like the way this forum does the notifications as I can ignore a thread for a couple of weeks and not get bugged by replies (or have to unsubscribe from notifications).
