I believe that some of you usually get annoyed if you get emails every time a reply is posted.
Don't worry, I'm included.

How to turn off :
Go to your Profile (The Profil button on the main menu)
Go to Preferences (Small tabs on the upper right menu)
and configure it!
Note : "Always notify me of replies : NO" <-- The main problem.
Recommendation : "Allow members to send me private messages :" keep it YES, because Private Message is very useful.

For experts, you can configure it by your own will..

Is it clear enough??