Alerts not sending to Mail Enabled Groups
This is caused by the security or distribution group to not allow non-authenticated users to send emails. The main reason why it would think the ChangeAuditor email account is non-authenticated as it normal does not have a mailbox attached to and is just an alias/name holder for alerts.
Within the exchange management console (EMC), find the security/distribution group and change the following:
Open EMC | Recipient Configuration | Distribution Group | Properties of group in question | Mail Flow Settings | Message Delivery Restrictions | Uncheck "Require that all senders are authenticated" box and this should allow the alerts to be sent through now.