Go to UserCP> Edit Options
Then you will see
"Use 'Email Notification' by default?
Using this option emails you whenever someone replies to a thread that you have participated in."
Then put that on no.
I still have no idea why this is standard on "On" to get this to no standard the template should be edited.
It would be easier that they should have just made a option for it in the admin panel.
well i like to be subscribed to some threads, just not others. sometimes i want subscribed to the ones i post it cuz i want to come back and see what others have said, others i just add my 2 cents and run know what i mean?
You can also just click for certain topics the box under the reply, which says "Email Notification: emails sent to you whenever someone replies. Only registered users are eligible"