The emails update instantly. You can almost IM, it's that quick. If you have opened the email with the 20 posts and read them all, then you delete it. When someone responds to that thread again, you get a new email. You don't delete it from your mail until you have read and responded, though. What I like about doing it that was is that when you click on the email link, it takes you right where you left off reading the last time - no digging thru threads to see where you left off. I think it's slick and fast. Sometimes I have 4 threads going @ one time, so then I know in what order to respond to them. kewl.