In order to receive email notifications for any event / incident you need to subscribe to a notification rule. Once this is completed any event under that notification rule will be notified to the recipient email address.
Go to Setup -> incident -> Incident rule
Select the rule you want to subscribe to. You will notice that “email me” column value is set to No.
Now got to Action -> Email -> Email me
Notice change in the column “email me” – it is now set to YES. You will also see a message that you have successfully subscribed to selected rule.
This means going forward you will receive notification for the event mentioned in this rule “target down rule”
Any notification will be now sent to the email address defined under