tenant.onmicrosoft.com values not reflecting local AD and Exchange

Joel Furnari 21 Reputation points

Our environment is hybrid, so I cannot make any changes from the Microsoft 365, Azure or Exchange admin center using powershell or UI so anything that starts with connect-msolservice will not work.

Due to recent security changes we have changed user logins to lfirst1234@tenant .com but their email addresses remain last.first@tenant .com.
Recently we have had a couple of new employees created, when the remote mailbox is enabled (from the local exchange management shell) it should generate the smtp:last.first@tenant .onmicrosoft.com alias instead it is generating lfirst1234@tenant .onmicrosoft.com in the Microsoft 365 Admin centers. This is causing some issues with internal email routing from systems as it is looking for the last.first@tenant .onmicrosoft.com address.

Local user account reads: UPN: lfirst1234@tenant .com
Attribute Editor: Every value reads last.first@tenant .com or tenant.onmicrosoft.com except for the userPrincipalName (last edited value) reads like above.
I have tried manually updating the users "inbox" in the exchange server to add the last.first@tenant .onmicrosoft.com the Sync Service manager is working and attributes are selected in the properties of the connectors but it never reflects the change on the Microsoft 365 Admin Center(s)
Does anyone have any ideas how I can force this change up to my Microsoft cloud environment I would be greatly appreciative. I believe I have tried searching everything my little Google-Fu brain can find but I am at a stand still


Active Directory
Active Directory
A set of directory-based technologies included in Windows Server.
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  1. Joel Furnari 21 Reputation points

    All we did was change the name the user uses to log in because a security initiative having the same log in username as their email address is inherently insecure, domain remains the same.

    AD is local and we have a exchange server local but our mailboxes are hosted in O365. It is referred to as a hybrid format. In short we cannot make changes to AD or Exchange from our cloud environment only our local as changes are only made upstream and not down.

    In the Microsoft 365 Admin center select the user, on the "Account" tab it shows "aliases" when you click "Manage username and email" I get the primary email address last.first@tenant .com, the username lfirst1234@tenant .com and under aliases lfirst1234@tenant .com and lfirst1234@tenant .onmicrosoft.com

    In the exchange admin center, select the user "General" tab and email addresses. Manage email address types and get the same values as the base 365 Admin Center.

    If I go to my local Exchange server and edit the user. On the tab that is labeled "email address" I can see the value(s) SMTP last.first@tenant .com and smtp last.first@tenant .onmicrosoft.com
    The last.first@tenant .onmicrosoft.com is what I need to push up to the cloud as that value is not represented in "the cloud" environment.

    1 person found this answer helpful.

  2. risolis 8,711 Reputation points

    Hi @Joel Furnari

    I am going a follow up about your concern and in case you need additional assistance please let us know.


    1 person found this answer helpful.