To opt out of receiving community emails, click on Manage Profile and then on Edit Bio. The section on account information contains a selection called Email Preference where you can opt-out of receiving community related emails from SAIMechE.

To opt out of receiving emails from the groups you belong to, click on Manage Profile and then on Preferences. You will see 4 group related notification settings which you can change.  Please note that these settings affect notifications from all your groups.