To the right of the folder for which you wish to disable notifications, click the button with three small dots:
Navigate to “Properties” and “Folder Settings” (by hovering). Click “Folder Settings”
Scroll to bottom of page to the “Email and Notifications” heading. Select how you would like, or not like, to be notified concerning interactions in this folder.
Ex. Deselect all checkboxes to remove all future notifications. Then click “Save” at the top of the page.