Restoring mailbox

Question

A user left and I had to recover them from the AD bin in ADAC. I then gave them a MS licence and thought their mailbox would appear after a while but it hasn't and I get this error under active users and their mailbox isn't showing under mailbox.

 Exchange: An unknown error has occurred. Refer to correlation ID: *******-****-Removed for privacy****-****-*******.;

Answer 1

Hi, 

It has been a while and I am writing to see how things are going with this issue. Have you had a chance to check the replies provided? Any update would be appreciated. 

We appreciate your patience and are here to help. Looking forward to your response.  
    
Best regards  

Henry-N - MSFT | Microsoft Community Support Specialist

Answer 2

Hi, 

Thank you for reaching out to the Microsoft Community. 

Regarding that you having problem when you try to restore a user mailbox. For further investigation I need to you ask you a question this will help us address the issue and assist you more effectively. 

Does issue happen to any other user in the tenant? 

How long after restoring the user did you assign the Microsoft 365 license? 

You could refer to this article to have a better view :Change the hold duration for an inactive mailbox | Microsoft Learn. And I found a post having a similar issue via this link Error: Exchange: An unknown error has occurred. Refer to correlation ID: | Microsoft Community Hub 

I'm sincerely sorry for the inconvenience that you've encountered. But I need to know more about your situation so I can help you better. We appreciate your patience and are here to help. Looking forward to your response! 

Best Regards, 

Henry N-MSFT | Microsoft Community Support Specialist