Exchange 2016 Hybrid Mailbox Conversion

Silver Contributor

Oct 19, 2023

To convert a shared mailbox to a user remote mailbox in a hybrid Exchange 2016 environment, you need to perform the following steps:

Make sure that the user account in Active Directory has the correct permissions. The user account must be a member of the Mail-Enabled Users group and the Mailbox Users group.
Make sure that the user's mailbox is not archived. If the user's mailbox is archived, you need to restore the mailbox from the archive before converting it to a user remote mailbox.
Make sure that the user's mailbox is not in litigation hold. If the user's mailbox is in litigation hold, you need to remove the litigation hold before converting it to a user remote mailbox.
In the Exchange Management Shell on the on-premises Exchange server, run the following command:

Set-RemoteMailbox -Identity <UserMailboxIdentity> -Type UserRemoteMailbox

Force a synchronization between the on-premises Exchange server and Exchange Online. To do this, you can use the following command:

Start-ADSyncSyncCycle -PolicyType Initial

In the Exchange Online Admin Center, verify that the mailbox type has been converted to user remote mailbox.

Useful links you can use:

Convert a shared mailbox to a user mailbox: https://learn.microsoft.com/en-us/microsoft-365/admin/email/convert-user-mailbox-to-shared-mailbox?view=o365-worldwide
Troubleshooting shared mailbox conversion issues: https://learn.microsoft.com/en-us/exchange/troubleshoot/user-and-shared-mailboxes/shared-mailboxes-unexpectedly-converted-to-user-mailboxes

Please click Mark as Best Response & Like if my post helped you to solve your issue.
This will help others to find the correct solution easily. It also closes the item.

If the post was useful in other ways, please consider giving it Like.

Kindest regards,

Leon Pavesic
(LinkedIn)

Forum Discussion

Exchange 2016 Hybrid Mailbox Conversion