Issue description 

Duplicate proxy addresses (such as SMTP aliases) in Exchange environments can cause user provisioning to fail or trigger synchronization conflicts. When creating or modifying Exchange mailboxes using ADManager Plus, these duplicates can block the successful completion of the operation.

Possible causes 

1. The same proxy address was manually assigned to multiple mail-enabled objects (users, groups, or contacts).

2. Legacy proxy addresses were not cleaned up after user deprovisioning or mailbox migrations.

3. Sync conflicts exist in hybrid Exchange environments with inconsistent address policies.

4. There is a lack of validation during bulk provisioning or template-based user creation.

Prerequisites 

• Ensure ADManager Plus is updated to the latest version that includes the proxy address duplication check feature.

• User accounts must be created using User Creation Templates under the Management tab.

• The technician must have permission to edit templates and configure Exchange mailbox attributes.

Resolution 

Enable proxy address duplication check in ADManager Plus

1. Log in to ADManager Plus.

2. Navigate to Management > User Management > User Templates > User Creation Templates.

3. Choose an existing template or click Create New Template.

4. Click Enable Drag-and-drop to edit the template layout.

5. Open the Exchange section of the template.

6. Hover over the Additional E-mail Addresses field and click the Edit icon.

7. In the pop-up window, check the box under Prevent Duplication to enable duplicate validation.

8. Select the scope for validation:

• Domain: To validate within the current domain.

• Forest: To validate across all domains in the forest (recommended for hybrid or multi-domain environments).

9. Click Done, then click Save Template to apply the changes. 

Tips  

• Test the template with a sample user before using it in bulk provisioning.

• Use forest-level validation in multi-domain or hybrid Exchange setups to prevent cross-domain conflicts.

• If a duplicate is found, ADManager Plus will raise a validation error and stop the provisioning process.

• Consider combining this feature with naming conventions or mailbox rules to avoid future duplicates.

How to reach support   

If the issue persists, contact our support team here.