Go to your User CP and edit options. Under Messages and Notifications there is a place called Default Thread Subscription Mode. Change the option to do not subscribe or no e-mail notification and you won't receive something for every thread you respond to.
I had the same problem and since my hubby and I share our personal e-mail address at home he wasn't thrilled that our mail box was full of YT stuff
So I played with it until I figured it out.
Leah
