I was looking for information on this topic. I see no one has responded to this message in 3 1/2 months. I know other forum software only sends one e-mail, with a message that there may be more.

I personally don't mind getting all of them, and this also gives people the option of not having to actually visit the site to keep up to date (such as in Admin Site Update forum, or whatever).

But it can get out of hand with a busy forum, and some of my users want to be notified of that someone has responsed to their posts, but not necessarily recieve 100 e-mails a day.

It would be great if that was a user selectable option in their Profile. I know that's asking a lot. Maybe an Admin system-wide option would suffice. That's probably asking a lot, too. But I think it's worth a shot trying.

I just noticed that there doesn't seem to by any flood control on e-mail notification of posts.  If a topic is popular and has 50 replies in a day, you would get 50 e-mails.

For example, we have a Word Association Game on our site that generates a lot of posts in a day and I was surprised that after I posted I was flooded with replies to my e-mail box.

I would recomend some kind of flood control that limits an e-mail being sent out to one per hour or one per 3 hours or something like that with a note saying this is the latest reply and their may be more, check the board for all the replies.  Or give people an option in their profile or something.