If Artifactory backup fails it will send an email notification to alert all the admin users in the case that one of the admin emails is not availble it will not send email to the next admin in the list and we will get the following error:
2019-05-01 08:34:19,205 [art-exec-32] [ERROR] (o.a.b.BackupServiceImpl:276) - Error while notification of: 'backup-daily' errors.
org.artifactory.util.EmailException: Failed to send e-mail to email@example.com due to Invalid Addresses
In setup where one might have the following Admin users :
Admin4 (invalid email)
Admin Users 1-3 will be notified via email of the backup not completing properly.
Admin Users 5-8 will not be notified.