Had an issue where the monitoring mailboxes were not being created for our Exchange organization. Starting with Exchange 2013 CU1, these mailboxes are created in the OU Monitoring Mailboxes under the Microsoft Exchange System Objects OU:
Previous to that, they were created in the default Users folder in Active Directory.
I had tried several things, I restarted the Health Manager service on all my Mailbox servers, I re-ran setup.exe /PrepareAD from the installation files, checked to ensure that the Exchange servers had permissions to that OU, deleted the Monitoring Mailboxes OU and re-ran Setup.exe /PrepareAD. Nothing worked. Deleting the Monitoring Mailboxes OU and re-running Setup.exe /PrepareAD did recreate the Monitoring Mailboxes OU, but there were still no Health Mailboxes.
The fix for this was really simple. The default email address policy in this environment was disabled, or scoped to only apply to a very specific OU that didn’t include the Microsoft Exchange System Objects->Monitoring Mailboxes OU.
We created a new email address policy that did apply to that OU:
After I created it, I ensured that it was applied:
After that, I restarted the Microsoft Exchange Health Manager service on all Mailbox servers and low and behold! All monitoring mailboxes were created!
Essentially if you do not have an email address policy that applies to the Health Monitoring mailboxes, they will not be created. The fix was simply, create and apply one to that OU.