I know there is a way to keep track of the threads you have posted in without being emailed everytime someone else does but i cant find it in the control panel.
If you click on the 'thread tools' tab at the top of your post, there's a 'subscribe to this thread' option.
Then there's a 'notification type' option. Change it to 'no email'.
Now when you log in or visit (I never log out) click on User CP. If anyone has posted to any thread you are subscribed to, it will show you the thread info in your control panel.