Notifications and the message tray
What is a notification?
If an application or a system component wants to get your attention, a notification will be shown at the top of the screen.
For example, if you get a new chat message or a new email, you will get a notification informing you.
Other notifications have selectable option buttons. To close one of these notifications without selecting one of its options, click the close button.
Clicking the close button on some notifications dismisses them. Others, like Rhythmbox or your chat application, will stay hidden in the message tray.
The message tray
The message tray gives you a way to get back to your notifications when it is convenient for you. It appears when you click on the clock, or press Super+M. The message tray contains all the notifications that you have not acted upon or that permanently reside in it.
You can view the notifications by clicking on the message tray items. These are usually messages sent by applications. However, chat notifications are given special treatment, and are represented by the individual contacts who sent you the chat messages.
You can close the message tray by pressing Super+M again or Esc.
If you’re working on something and do not want to be bothered, you can switch off notifications.
Open the Activities overview and start typing Notifications.
Click on Notifications to open the panel.
Switch Notification Banners to OFF.
When switched off, most notifications will not pop up at the top of the screen. Notifications will still be available in the message tray when you display it (by clicking on the clock, or by pressing Super+M), and they will start popping up again when you switch the toggle to ON again.
You can also disable or re-enable notifications for individual applications from the Notifications panel.