Exchange admin center: Migrate from Google Workspace; Mail User, Create contact failed (The email address is already being used.)

Kat 96 Reputation points
2021-02-16T20:27:20.693+00:00

Hello,

Am following "Perform a Google Workspace (formerly G Suite) migration" instructions and am now at the step "Provision users in Microsoft 365 or Office 365".

Am attempting to create Mail Users, in order to add the external email address "userXYZ@gsuite.mycompany.com" to my active users, as well as the proxy/alias email address "userXYZ@infotech .mycompany.com", as described in the instructions to the normal email address "userXYZ@mycompany.com".

Am getting the "Create contact failed" with "Error: The email address is already being used. Please choose another email address." I am assuming that is because there are active users with normal email address "userXYZ@mycompany.com" (with Microsoft 365 Business Standard license).

  • How can I add the required email addresses, to my active users, please, so I can continue with the migration process?
  • Does the process work with active users? Are Mail Users different from Active Users?
  • Would I need any special rights to add these two additional email addresses to my active users?

Any input would be greatly appreciated. My company really wants to move away from Google and over to Microsoft, but of course would like to migrate their existing emails.

Kind Regards!

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Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Migration: The process of making existing applications and data work on a different computer or operating system.
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  1. Kat 96 Reputation points
    2021-02-19T17:07:37.58+00:00

    Hello,

    Was able to activate the migration for all the existing users and all mailboxes are synced now.

    Following "Perform a Google Workspace (formerly G Suite) migration" selectively and activating the migration part worked. However, I did not make use of either subdomain 'gsuite' or 'o365', since I was unable to add any of these to the active users that were already present and had user mailboxes. Furthermore, I did not migrate a "copy" and I did not attempt to merge mail folders, in particular, because these "copy accounts" would have exceeded our licences.

    Thank you very much for your support and input! It definitely helps a lot to have someone with knowledge to write to, it is especially helpful in making sense of the system.

    Unsure how to combine my comments to a cohesive description of the situation I encountered, so others may get some value from this also? Is it possible to accept your answer and point to the comment section too?

    Best wishes!

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  1. Eric Yin-MSFT 4,386 Reputation points
    2021-02-17T08:32:13.877+00:00

    Hi,
    Can you post the result of the following command: 

    get-recipient userXYZ@mycompany.com|fl *addre*

    In my test, an exisiting user with userXYZ@mycompany.com would not cause a error, how did you create the mail user? EAC or powershell? Can you post the snapshot of error info?
    Besides, why do you already have user with userXYZ@mycompany.com? If the migration success and during the step mailuser converted to user mailbox, you would get same error because there is an existing userXYZ@mycompany.com.

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