You are migrating mailboxes to Office 365, and the following error message is showing: MigrationPermanentException:…
Office 365 mailbox not showing in Exchange Hybrid on-premises
An Exchange Hybrid configuration is set up in the organization. When you look in the on-premises Exchange admin center, the Office 365 mailbox is not showing. The mailbox shows only in Office 365. Why is this happening, and what is the solution for Office 365 mailbox not showing in Exchange Hybrid on-premises?
Table of contents
Check mailbox in Exchange Online and Exchange on-premises
There is an Office 365 mailbox when you look in Microsoft 365 Exchange admin center. In our example, the user mailbox is Alison Bell with the email address Alison.Bell@exoip.com.
When you check the on-premises Exchange admin center, the mailbox doesn’t show up. Even a search will not show you the mailbox.
Let’s try to find the mailbox with PowerShell. Start Exchange Management Shell as administrator. Run Get-RemoteMailbox cmdlet. You will get the output that the object couldn’t be found.
[PS] C:\>Get-RemoteMailbox -Identity "Alison.Bell@exoip.com"
The operation couldn't be performed because object 'Alison.Bell@exoip.com' couldn't be found on
'DC01-2016.exoip.local'.
+ CategoryInfo : NotSpecified: (:) [Get-RemoteMailbox], ManagementObjectNotFoundException
+ FullyQualifiedErrorId : [Server=EX01-2016,RequestId=ac7b9c98-6913-4c83-a35c-4351e7308fe4,TimeStamp=6/21/2021 9:2
5:50 PM] [FailureCategory=Cmdlet-ManagementObjectNotFoundException] 1B6A5890,Microsoft.Exchange.Management.Recipie
ntTasks.GetRemoteMailbox
+ PSComputerName : ex01-2016.exoip.local
Why is this happening and what is the solution for Office 365 mailbox not showing in Exchange Hybrid on-premises?
Why Office 365 mailbox is not showing in Exchange admin center
The Office 365 mailbox does not show up in Exchange on-premises because:
- You create an on-premises Active Directory user account and assign a license to the mailbox without the Enable-RemoteMailbox cmdlet.
- You create an on-premises Active Directory user account and create the mailbox in Office 365 (cloud) without the Enable-RemoteMailbox cmdlet.
Let’s have a look at how to fix the Office 365 mailbox not showing in Exchange on-premises.
Solution for Office 365 mailbox not showing in Exchange admin center
Run Exchange Management Shell as administrator and run the following three cmdlets.
Step 1. Run Enable-MailUser cmdlet to mail-enable the user that isn’t already mail-enabled.
[PS] C:\>Enable-MailUser -Identity "Alison.Bell@exoip.com" –ExternalEmailAddress "Alison.Bell@exoip365.mail.onmicrosoft.com"
Name RecipientType
---- -------------
Alison Bell MailUser
Do you get an error after running the above cmdlet? Read the article ExchangeGuid is mandatory on UserMailbox.
Step 2. Run Enable-RemoteMailbox cmdlet to link the cloud mailbox in the cloud-based service for the existing user in the on-premises Active Directory.
[PS] C:\>Enable-RemoteMailbox "Alison.Bell@exoip.com"
Name RecipientTypeDetails RemoteRecipientType
---- -------------------- -------------------
Alison Bell RemoteUserMailbox ProvisionMailbox
Step 3. Force sync Azure AD Connect with PowerShell.
PS C:\> Start-ADSyncSyncCycle -PolicyType Delta
Verify Office 365 mailbox showing in Exchange on-premises
Check in the on-premises Exchange admin center that the Office 365 mailbox shows up.
Another check, but this time in Exchange Management Shell. Run Get-RemoteMailbox cmdlet.
[PS] C:\>Get-RemoteMailbox -Identity "Alison.Bell@exoip.com"
Name RecipientTypeDetails RemoteRecipientType
---- -------------------- -------------------
Alison Bell RemoteUserMailbox ProvisionMailbox
Everything looks great!
Read more: Create Office 365 mailbox in Exchange Hybrid »
Conclusion
In this article, you learned why the Office 365 mailbox is not showing in Exchange Hybrid on-premises. The solution to this problem is to run both the Enable-MailUser and Enable-RemoteMailbox cmdlets against the on-premises Active Directory user. After that, the Office 365 mailbox shows up in the on-premises Exchange Server.
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This works great for regular mailboxes, thank you!
How would we update Distribution group, Shared Mailbox and Room Mailbox attributes created before we had a Exchange 2016 Management Server to have them show in Exchange 2016 Admin Center?
This is the best and simple article explained. Kudos Man
After searching for about an hour to no success, this worked perfectly. Thanks Ali
This is fab, been messing around removing licenses, un/re syncing etc. So much simpler.
This blog was a life saver. Thanks for posting!
Muchas gracias, era lo que me faltaba!
Excellent article Ali, worked like a charm! Thank you so much!
This was very helpful, thanks so much!
User is showing on on-Premises but the same user is not showing on online exchange
Thanks for the very clear instructions and we were able to resolve this same issue.