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msidnamFlag for United States of America

asked on

cloud only mailbox now needs to be a hybrid on prem user.

We currently use AD Connect to sync our on prem users/groups/passwords to Office365. We created a few users in O365 only because, at the time, they would not need any on prem access. That has now changed.

I'm trying to see the best way to do this while keeping a single account and not delete any teams or emails. My initial though was to delete the O365 account (O365 should soft delete it and give me 30 days before fully deleting the account), create the user in our on prem AD with the same user account info and then attach the old mailbox to the newly created on prem account.

My problem with that is when i attach the account that was soft deleted to the on prem account does it create the proper remote mailbox? If i create a remote mailbox, wont it try to either create a new one in the cloud or perhaps override the one that was soft deleted?

Not sure of the direction to go.

Thank you.

Avatar of DEMAN-BARCELO (MVP) Thierry
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You don't have to delete the account on O365.
Just create the user in AD with the same UPN and the same Mail in Active Directory. Ideally, the mail and the UPN should be identical. If you have Exchange, don't enable the mailbox for this user.
=> ADConnect will automatically attach the AD account if the UPN is identical, or the email if the UPN is not found.

Take care that if the password is synchronized by ADConnect, the Cloud User will have his old password replaced by the AD Password.

A full sync is preferable to ensure the correct matching.
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1. As stated earlier create your AD user account with the same UPN

2. In Exchange online verify the remoteroutingaddress it has for the mailbox  it would be-

3. Link the AD account to the o365 mailbox in the cloud using the samaccountname of the on prem user and the remoterouting address in the cloud

From your ON PREM Exchange Management shell you will run the following command.

Enable-RemoteMailbox "samaccountnameoftheuser" -remoteroutingaddress 

 (whatever the remoteroutingaddress is for the user in o365)

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Thank you everyone. M A had a link that explained what you were all talking about. I was able to use that link and the user was changed from cloud sync to on prem.

Nice...I'm glad you got it sorted out.