E-Mail notifications can be used to alert you if a backup has not occurred in a certain period of time. They can also be used to send email notifications to a ticketing system that we do not currently support.
Click on Email Notifications -> Create a New Email Notification
Give the email notification a name. You can have multiple notifications with different settings. For example I could have one that I set for one Company that is escalate after 1 day and I can create a second notification for a different company that has a 3 day escalation. You could also just have one global notification that covers all clients for a 3 day escalation by not choosing any filters.
Another recommendation I would make is to at a minimum include the Failure and No Result status in your notifications. Keep in mind the email notifications will send an email for every backup that meets the criteria so if you have 50 backups in a failed state turning this on will send you 50 separate emails displaying each backup in that state.