Recently I have been in a situation where I have Exchange 2016 Hybrid Exchange Online. Exchange 2016 Active Directory DS is synched to Azure Active Directory using Azure Active Directory Connect Apps.

Problem:

I am looking for the best way to convert the Regular licensed mailbox (Size less than 50 GB) into a shared mailbox without a license.

As far as I know, a Shared mailbox of less than 50 GB do not required any license assigned, but when I convert the mailbox from the Microsoft 365 portal and cancel the license, the mailbox is gone missing.

The same happened when I used PowerShell or Microsoft Graph to convert the Regular mailbox to Shared Mailbox using the Set-Mailbox user.name@abc.com -Type Shared cmdlet and then cancel the license. It goes deleted.

Solution

After lots of googling, I found the below solution.

First, Set the remote mailbox to shared On-premises with Set-RemoteMailbox.

Set-RemoteMailbox <user> -Type Shared

Let it sync, and verify the Microsoft 365 mailbox is shared as well.

get-mailbox <user> |FL *type* 

If it’s not set to shared, then it first needs to convert to a shared mailbox, confirm its set and then remove the license.

Conclusion

You learned Best Practice and Steps for converting Regular mailbox to Shared Mailbox without any license. Did you enjoy this article? You may also like How To Migrate Exchange Server 2012-R2 Essentials to Exchange Server 2022 Essentials. Don’t forget to follow us and share this article.