System Administration & Network Administration
microsoft-office-365 azure-active-directory
Updated Wed, 31 Aug 2022 18:10:06 GMT

How do I manage email addresses when using directory synchronization?

We use Office 365 and we've set up Azure AD Sync to synchronize our user data.

Sadly, after doing so, all our email aliases, which we previously configured in the Office Admin Portal, are now gone and we are unable to edit them in the web UI. Additionally, I see no way to edit them through the Users and Computers snap-in.

How can I configure our email addresses?


I found the solution in an article titled Add Email Alias (Secondary Email) to Office 365 Account that has AD DirSync:

  1. On a domain controller, open ADSI Edit by running adsiedit.msc or opening the snap-in from the Start menu.
  2. Open the Default naming context. If it is not shown in the tree, connect to it using the appropriate context menu option. The default connection parameters will usually be fine.
  3. Navigate to the OU that contains the user you want to edit, then open the Properties of that user.
  4. Navigate to the ProxyAddresses attribute and Edit it.

    The primary email address should be added as, notice the uppercase SMTP prefix.

    All additional alias addresses should be added as, with a lowercase smtp prefix.

Alternatively, this property can also be edited through the Active Directory Users and Computers snap-in. You just need to enable the advanced features by going to View Show advanced features. Afterwards, you will have an additional Attributes tab in the dialog where you edit the user. Here you will also find the ProxyAddresses attribute.

You will have wait for Azure AD Connect to run another synchronization cycle before your changes appear in the Office 365 Admin Portal. If you want to speed up the process, you can force a synchronization from PowerShell:

Start-ADSyncSyncCycle -PolicyType Delta