OS X El Capitan: Receive or stop notifications
Many apps use notifications to let you know about events, updates, or changes. Notifications appear briefly in the top-right corner of the screen or stay there until you dismiss them. You can set options in Notifications preferences to change how notifications appear, and stop or pause them.
View notifications you receive
Get details: Click Show, or click the notification.
Respond to email or text messages: Click Reply.
Save an AirDrop item to the desktop: Drag the item from the notification to the desktop. (Otherwise, AirDrop items are saved to the Downloads folder.)
Respond to calls: Click Accept or Decline. To reply using the Messages app, click the disclosure triangle next to Decline, then choose Reply with Messages.
Choose when to update software: Click Later, then choose a time. For more information about updating, see Keep your Mac up to date.
Repeat a notification: Click Snooze. The notification reappears fifteen minutes later. To choose when the notification reappears, click and hold Snooze, then choose a time.
Stop or pause notifications
You can set options in Notifications preferences to turn off notifications for specific apps or to pause all notifications. Choose Apple menu > System Preferences, then click Notifications.
Turn off notifications for an app: In Notifications preferences, select the app on the left, then choose None for the app alert style on the right. You no longer receive any notifications for the app.
Stop notifications during specific hours: In Notifications preferences, select Do Not Disturb on the left, then set options.
Pause notifications until midnight: Hold down the Option key while you click the Notification Center icon in the menu bar.
When Do Not Disturb is on, the Notification Center icon in the menu bar is dimmed. You don’t see or hear notifications arrive; they are collected in Notification Center where you can view them later.