Unable to use aliases when user accounts are stored on a different domain to the exchange server


Microsoft Outlook is not populated with alias addresses, and users cannot send messages from an alias address using the subject line trigger 'sendas:alias@domain.com.

Your setup is such that proxy addresses are only populated in Active Directory on a different domain (or subdomain) to the one which the user is logged in.


The Email Alias Manager Agent uses LDAP queries to verify a users’ available email aliases.

When an LDAP search is performed against a domain, the search considers all trusted domains and subdomains to be separate entities. This means that it does not recursively search all sub-domains from the root domain - each domain must be searched independently.

As such, the Email Alias Manager Agent can only search one domain or subdomain. So, if Email Alias Manager is searching an incorrect domain, the aliases will not be populated in Microsoft Outlook.


You can specify the domain (or sub domain) where Active Directory is populated with proxy addresses in the Windows Registry. This should be set on each machine which has the Email Alias Manager Outlook add-in installed.

If you are not familiar with the Windows registry, you may wish to read about it before attempting any changes.

Note: We strongly advise that you complete a backup of the registry before to following these steps. For further information about how to back up and restore the Windows Registry, see Microsoft KB Article 322756: How to back up and restore the registry in Windows, in the Microsoft Knowledge Base.
  1. Click Start and then Run.
  2. Enter regedit and click OK to open the Registry Editor.
  3. Expand the tree in the left-hand pane and navigate to the path below:

    HKEY_CURRENT_USER\SOFTWARE\Exclaimer Ltd\Email Alias Manager
    Note: If this key does not exist, you should create it.

  4. In the right-hand pane, right-click and select new > string value:
  5. Name the string value: LDAPRootString.
  6. Double-click the value to edit it.
  7. Enter the LDAP string for the domain where Active Directory is populated with proxy addresses. For example: LDAP://DC=Child,DC=Domain,DC=local
  8. Click OK and the change should take effect immediately.

How To Troubleshooting