Option+Click the Notification Center menu bar icon, it will turn grey when disabled To re-enable Notifications, just option+click the menu bar icon again. It will turn black to signify that it’s active again. read more
Click Notifications on the left panel. Your Settings page will have a navigation panel on the left-hand side of your screen. The Notifications option is listed next to world icon on this navigation panel. It will open your Notifications Settings. read more