Back=right mouse click.
The following HA events can have notifications sent:
HA Found Switchover
HA Found Child Server Failure
HA Found Recovered Child Server
Configuration Sync Failure
Click the "Send a message when..." check box to have a message sent for the specific HA event.
Use the default message or add your own custom message.
Change the recipient, if needed on the Notifications Email Settings page.
Click Save.