Troubleshooting Mailbox Sync

3 min

Issue

A hybrid shared mailbox is not syncing into Activate during the mailbox sync process. The Activate_MailboxSync.log file shows that the mailbox has been found in Entra but no Mailbox resource is being created in Activate.

Solution 1

The most likely cause of this issue will be the Azure Users sync. If an Activate user cache entry that matches the mailbox's UPN is not found then the mailbox resource may not be created. This can be determined by looking at the ADCache table (AzureID and AzureUPN columns) and checking whether the local AD account has an Entra ID cloud account mapped to it.

To try and resolve this issue follow these steps:

In Activate Studio browse to Roles > System Roles > Azure Users.

Confirm there are two Members parameters

Members OU Reference = OU=Users,DC=mytenant,DC=onmicrosoft,DC=com

Members String = (exAzureID=*)

Browse to Resources > Mailboxes

Confirm there is one Members parameter referencing OU=Users,DC=mytenant,DC=onmicrosoft,DC=com. There also may be another Members parameter referencing the local domain.

Run a full Azure Sync, this should be setup in the scheduler to run on a nightly basis. To force a full sync during the next scheduled run:

Delete Resources/ActiveDirectory/External Directories/Azure/UserSync_Token

This may take some time depending on the size of the domain so it's recommended to run this outside of business hours.

After running these steps the AzureID and AzureUPN should now be present on the local AD entry in ADCache. Running the Mailbox sync again now should import the missing mailboxes.

Solution 2

If you are still encountering issues then it could be the System Roles > Users role, ensure that the Members parameters include the OUs in which the on-prem mailbox accounts reside. The on-prem mailbox accounts must exist in ADCache table for the mailbox resource to be created, so ensure the Users background sync is operating. This can be found here:

=//System/Tasks/Background/MaintenanceScript

=//Resources/Schedulers/Nightly - License Statistics

If you've found this not be configured correctly, then enable the scheduler, once it has run then repeat the steps in Solution 1 to force a full Azure Sync.