How Can I Restrict Email Notifications from Moodle Forums?
You can decide for yourself whether or not you wish to be notified per e-mail in regards to new posts in the course forum.
Click in the course on "Forums" in the "Activities" section. You will see an overview of all forums and can determine which forums you wish to subscribe or unsubcribe to.
You can also summarize forum posts in your profile section. On the upper right side, click on your name and then "Preferences". Under "User Account", select "Forum preferences". In the field "Email digest type" you can get a daily summary of forum posts.