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AtanasM's avatar
AtanasM
Iron Contributor
May 31, 2020
Solved

Some On Premise mailboxes are provided with wrong external email address in Office 365

In some OnPremise mailboxes, the associated “mail users” in O365 are provided with the wrong external email address. The target address for mail users is set wrong by Azure AD Connect. Our customer...
Azure Active Directory (AAD)
Identity Management
microsoft 365
  • PeterRising's avatar
    PeterRising
    Sep 20, 2020

    Jjsilva AtanasM 

     

    Apologies, I lost track of this issue.  The reason that the email address could not be changed is the Source of authority is on-premises AD, not Azure AD.  To change this email address you would need to do so from the on-premises Exchange Admin Centre, not the Exchange Online one.

AtanasM's avatar
AtanasM
Iron Contributor
May 31, 2020

PeterRising could you explain more precisely the phrase:

"setup in on-premises AD with a domain.local UPN suffix as opposed to the routable domain name".

 

Thanks inn advance.

PeterRising's avatar
PeterRising
MVP
May 31, 2020

AtanasM 

 

In Active Directory Users and Computers, open one of the affected users and go to the Account tab.

 

You will see that the UPN is set to username@domain.local.  Under the domain suffix part of the UPN, click the dropdown and select the actual email domain and the UPN should change to username@domain.com 

 

If you don't see the domain in the dropdown, you may need to add it as an additional UPN suffix in Active Directory Domains and Trusts.  However, as you have said that some of your users are syncing correctly, I am guessing the domain will be available to you in the dropdown.

  • AtanasM's avatar
    AtanasM
    Iron Contributor
    Jun 02, 2020

    PeterRising I checked in Microsoft 365 admin center and Active Directory and the usernames are displayed correctly with the correct domain. The issue exists only in "Contacts" in Exchange Admin Center. Please check the attached screenshot.
    What do you think, what could be the reason for that and how can I solve it?

    • PeterRising's avatar
      PeterRising
      MVP
      Jun 02, 2020

      AtanasM 

       

      Hi, so in your Exchange on-premises server, are the objects showing with the correct primary smtp email addresses?

      • AtanasM's avatar
        AtanasM
        Iron Contributor
        Jun 03, 2020

        Hi PeterRising do you mean in Active Directory?

        Please provide the path how to check  this.

        Thanks in advance.

  • AtanasM's avatar
    AtanasM
    Iron Contributor
    May 31, 2020

    PeterRising I will chech this on Tuesday.

    Thanks!

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