Insert backup status into email subject
For a busy system admin, it could be helpful to see the backup status as "SUCCESS" or "FAIL" in the email subject, so the admin doesn't need go through every notification email whether any backup failure is present.
insert "SUCCESS" into email subject, if all accounts backed up successfully
insert "FAIL" into email subject, if any of accounts cannot be backed up for any reason.
Make status with capitals, OR insert icons similar to hotels.com email notifications, so admin can easily distinguish and take necessary actions.
Apply above for all notifications where possible.