On the menu bar at the top of the page (next to Notifications), click Settings. At the left side of that page, under My Settings, all the way down at the bottom of the list is a heading "DBTech - Post Thanks" followed by Settings (again). If you click that 2nd Settings, you can turn off email and "notifications". No idea what sort of notifications (maybe live popups if you're logged in on the site?) that means.