I have configured the mail notifications in tuleap, the thing is that it sends email to all users of a artifact irrespective of their status. In the help document provided by tuleap:
https://tuleap.net/doc/en/user-guide/tracker-v3.html#event-role-based-notification-settings
It shows how to configure for each and every groups involved in an artifact, but I don't find any settings available in tuleap tool. I don't want users to get an notification for each and every activity taking place inside an artifact.
This is because is was a feature in the old version of the tracker system (V3), and is no more available in the last version (V5).
I know they are already studying the possibility to unsubscribe to an artifact, but if you need more, you should bring the subject on the mailing list here