Re-Creating a synced account from AD to 365 not allowing email to be setup correctly.

Question

I created a user in local AD and synced it to 365. I assigned a license but it never finished creating the mail account. I deleted the AD user, synced it to 365, and then permanently deleted the user in Entra. I then tried to re-create the AD account, synced it to 365. When I add a license to the re-created account that is synced, I am getting the error: Exchange: An unknown error has occurred. Refer to correlation ID: dfbda13e-ebf5-4b8f-9a24-3d14e0c51eb7. When I assign a license for 365, the email address assigned is the account identifier instead of the typical username. It's like a ghost in the system, and I don't know where else I need to delete the old account/alias from to make this work. Any help would be appreciated.

Answer 1

Hi Jason Franklin,

Thank you for posting your question in the Microsoft Q&A forum.

Do you create the new AD account with the same name? What about create a new account with different name?

Noticed that you have permanently deleted the user in Entra, please also confirm that this account does not exist in Deleted users from Admin center and AAD side.

Since you tried to assign license to the old account to enable mailbox, please use the following command to check if any soft deleted mailbox still remains for the old account in Exchange Online:

Get-Mailbox -SoftDeletedMailbox | fl ExchangeGuid,Guid,PrimarySmtpAddress

Then use the following command to delete is permanently:

Remove-Mailbox -Identity Exchange_Guid -PermanentlyDelete -Confirm:$False

 

You can check this article for more details: How to purge mailboxes in Exchange Online - Microsoft Community

If suggestions above still cannot resolve your issues, you also can raise an O365 support ticket from Admin center to see if we can get help to check and resolve from O365 backend server side.

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