If a license is not assigned to the user, the mailbox may be disconnected. This can cause potentially irrecoverable data loss.
Additionally, when you view the properties of the shared mailboxes in the Office 365 portal, you may receive the following error message:
- If the mailbox in Exchange Online has been disconnected, temporarily assign a license to the user. This automatically reconnects the mailbox.
- Move the mailbox back to the on-premises Exchange environment. To do this, create a new migration batch and select Move from Exchange Online as the batch type.
- Convert the mailbox to a shared mailbox. To do this, open the Exchange Management Shell, and then run the following command:Note When the mailbox is converted to a shared mailbox, the user account that's associated with the mailbox is disabled. Directory synchronization is set up by default to include disabled accounts. However, if this configuration is changed, it can cause the user account to be deleted from Exchange Online.
Set-Mailbox –identity <mailbox identity> -Type Shared
- Move the shared mailbox to Exchange Online, and then remove the license.
You can't use the Set-RemoteMailbox cmdlet to set the Type parameter of the mailbox to Shared. Therefore, you must move the mailbox back to the on-premises environment in order to convert the mailbox.
Still need help? Go to Microsoft Community or the Exchange TechNet Forums.
Article ID: 2710029 - Last Review: Dec 16, 2016 - Revision: 1