Possible Duplicate:
Feature Request: Is it possible for subscriptions to be more customizable?
From a comment on this post:
The problem with the subscriptions as they stand is that you end up getting crazy spam in your inbox if you are subscribed to a whole project's worth of cases. Being subscribed to a whole project is worth while in our case but it does make for a lot of 'so-and-so assigned case X to so-and-so' emails that you usually don't care about. Is there any way of making a subscription more cusotmizable so that you only get an email when, for example, the description of the case changes?