A couple of forums that I've used in the past utilize a system of e-
mail updates that I've found useful, but different from the norm.  
Instead of sending an e-mail every time someone responds to a thread  
to which you are subscribed, they send you one e-mail as soon as  
someone responds after your post, and in the e-mail they inform you  
that you won't receive any more notices until you've returned to the  
site to avoid filling your inbox. If you do return to the thread to  
catch up, you're added to the queue to receive a notice after the next  
response.

As I was experiencing these forums from the user-side, I don't recall  
which packages or services had this set up, so I was wondering if  
anyone could point me towards a forum or set of forums that follow  
this way of doing things.

Thanks!

Alex Jones
www.SilverSpider.com