As a Submittable user, you can control whether you receive email notifications by toggling the Email Notifications checkbox in your account Settings area.
Click on your initials in the upper right corner of your screen.
Scroll down until you see the Email Notifications section.
Leave the box checked to receive all notifications from Submittable. Or uncheck the box to stop receiving all notifications from Submittable. Unchecking the box will prevent you from receiving both assignment notifications (if you are an organizational team member) as well as any notifications related to submissions you've made as a submitter.