How to delete a badly restored shared mailbox?

Question

How to delete a badly restored shared mailbox?

Aho Bakashi 20

Problem #1: About six weeks ago I inadvertently deleted a shared mailbox in my tenant. I restored it with a Powershell command, but it came back as a zombie. Nobody could access it. I could not edit it. M365 support helped me restore the deleted mailbox again to a new shared mailbox which has all the data. The problem is I cannot assign the original email address to the properly restored mailbox because the zombie mailbox won't let it go.

I opened a new ticket with M365 Support and after several days they said they could not help and that I had to open a support ticket with Entra Support, which leads to problem #2.

Problem #2: I purchased a standard Azure support plan for $100/month so that I could open a technical support request in the Entra portal, but I still can't do it. The only problem types I can open Entra tickets for are Billing and Subscription services.

Any tips for problem 1 or problem 2?

My initial mistake was using this Powershell command to do the mailbox restore without supplying a user password:

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Answer 1

Austin-H 6,990 Microsoft External Staff Moderator

Please understand that our forum is a public platform, and we will modify your question to cover your organization's ID in the description. Please note that you should hide this personal or organizational information the next time you post a bug or some information to protect personal data.
Hello @Aho Bakashi
Thank you for posting question to Microsoft Q&A Forum.

According to this issue, may I know if you could provide more information about the troubleshooting steps that M365 support provided to you? Did you execute any PowerShell script?
When you mentioned that the zombie mailbox won't let it go - does it mean that you could not delete the mailbox and use it's address to replace it on new shared mailbox?
If you still want to delete the zombie mailbox, please consider running this command in Exchange Management PowerShell:

Remove-Mailbox -Identity "ZombieMailboxName" -Permanent $true

At this part, it should return an error message if this mailbox could not let it go. Please provide me a screenshot of this message.

If this is about mailbox provisioning issue, only M365 Support could check on this from back-end side, not in this forum as we do not have access to internal system.
For your second question, this issue is not related to Azure, it's more about Exchange.
Please check on your private message as I also sent you a message.
I am looking forward to your update.

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Aho Bakashi 20 Reputation points

2025-11-07T18:20:08.1+00:00

Hello Austin-H,

Thank you for your reply. I believe I already tried the Remove-Mailbox command, but I ran it again so you could see the error message. Basically, I believe the error is saying the shared mailbox does not exist, which is funny because I can see it in the Exchange M365 web portal.

Yes, I want to delete the "zombie" mailbox so I can reuse the email address. The public send messages to that email address to get certain services from the organization.

I agree with you that this seems like a M365 support issue. However I have spoken to three support agents from M365 support and they have all punted the problem to the Azure team. I'm beginning to fear I will never be rid of this zombie.

I noticed that the Powershell command that caused all the trouble got censored in my original post for PII. Here it is again. One tech told me I should not have used the -WindowsLiveID parameter.
Austin-H 6,990 Reputation points Microsoft External Staff Moderator

2025-11-10T03:17:43.4233333+00:00
Hi Aho Bakashi
Thank you very much for your update.
According to this issue, I have reviewed the error message and found these articles:
https://martinsblog.dk/exchange-hybrid-office-365-cannot-delete-shared-mailbox/
https://community.spiceworks.com/t/error-deleting-office-365-shared-mailbox/665729/2
https://anandthearchitect.com/2021/11/24/exchange-online-remove-mailbox-the-following-error-occurred-during-validation-in-agent-windows-liveid-agent-unable-to-perform-the-save-operation-sharedmailboxname-is-not-within-a-valid/
*
Note: Microsoft is providing this information as a convenience to you. The sites are not controlled by Microsoft. Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. Please make sure that you completely understand the risk before retrieving any suggestions from the above link*

May I know if you are also having an Exchange hybrid environment from your end? If yes, consider following the first article with the PowerShell if you have the hybrid environment.

From the third link I provided, the Get-MsolUser has been deprecated, consider using Microsoft Graph: https://learn.microsoft.com/en-us/powershell/microsoftgraph/installation?view=graph-powershell-1.0 (view this link for instruction).

Then you could try to run this PowerShell command.

Get-MgUser -Filter "proxyAddresses/any(x:x eq 'SMTP:******@domain.tld')" or Get-MgUser -UserId "******@domain.tld" then if you have information, run: Remove-MgUser -UserId "<ObjectId or UPN>"

Once the system returned information, please reply to me before proceed to delete (I need to see it before suggesting you further steps). You could hide your personal information and post the screenshot here or directly answer me via Private Message.
Austin-H 6,990 Reputation points Microsoft External Staff Moderator

2025-11-11T05:44:03.2966667+00:00

Hi Aho Bakashi
It has been a while since your last approach.
Please let me know if you have checked my response.
Austin-H 6,990 Reputation points Microsoft External Staff Moderator

2025-11-13T12:46:39.78+00:00

Hi Aho Bakashi
I am looking forward to your response.
Please let me know if you could share with me your recent update.

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How to delete a badly restored shared mailbox?

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