Can't revert from "Mail User" to "User Mailbox"

Question

Can't revert from "Mail User" to "User Mailbox"

Axel C-FR 0

Hello,

One of my users lost complete access to her mailbox, I believe her Office licence got "removed" for 2~ hours then put back but nothing came back to normal...

O365 Admin Center shows this message on their profile :

Exchange : The execution of cmdlet Enable-Mailbox failed. {"error":{"code":"InternalServerError","message":"Internal server error","innererror":{"message":"Internal server error","type":"Microsoft.Exchange.Admin.OData.Core.ODataServiceException","stacktrace":"","internalexception":{"message":"Unable to retrieve disconnection date of previous archive.","type":"System.InvalidOperationException","stacktrace":"","internalexception":{"message":"Access is denied.","type":"System.UnauthorizedAccessException","stacktrace":"","internalexception":{"message":"Access is denied.","type":"System.Runtime.InteropServices.COMException","stacktrace":""}}}},"* Email address is removed for privacy *":"#Collection(String)","@adminapi.warnings":[]}}

"Enable-Mailbox" shows this over Powershell :

"Unable to retrieve disconnection date of previous archive."

Note : I don't think she ever had an Archive because it was already disabled over Exchange On-Premise

"Get-Mailbox" generates this :

"The operation couldn't be performed because object '* Email address is removed for privacy *' couldn't be found on

'MR1P264A08DC002.FRAP264A008.PROD.OUTLOOK.COM'"

I don't know if it's relevant information but the rest of Office apps is totally fine.

I sent a ticket to Microsoft, which is pending for 1 month and a half now... Apparently the issue doesn't come from Exchange Online but from their internal servers ? (according to O365's message) yet no update from them.

I also tried to apply a different licence, edit msExchMailboxGuid (generate a new one / 0000-00[...]), msExchArchiveName, msExchRemoteRecipientType (and lot more Powershell commands) according to different forums but nope...

I'm running out of options and I'm worried that it wont be recoverable because it got past their retention policy of 30 days...

Sorry if I probably forgot some important information, there was so much done but nothing worked.

1 answer

Your answer

Answer 1

Sharon Zhao-MSFT 25,751 Microsoft External Staff

Hi @Axel C-FR

Welcome to Q&A!

To better assist you, please provide the following details regarding your environment and the issue:

What is your environment? A hybrid or purely online one?
Was the affected user’s mailbox migrating from an on-premises to Exchange Online, or was it created directly in Exchange Online?
Please run the following command to retrieve the properties of the affected user and share the output with us:

get-User -Identity AffectedUser | Format-List

Based on the information you’ve provided; it appears that the mailbox may have been permanently deleted due to the retention policy.

However, there is a potential workaround to restore the mailbox data if the affected user had previously logged into Outlook for Windows before the issue and the data remains cached on the client. If this is the case, we can export the cached data into PST file, create a new account and mailbox for the user, and import the data back into the new mailbox.

Please refer to the following steps to export the data:

At the top of the ribbon in classic Outlook, choose File.
Choose Open & Export > Import/Export.
Choose Export to a file > Next.
Click Outlook Data File (.pst) > Next.
Select the name of the email account to export, as shown in the picture below. Only information for one account can be exported at a time. Make sure that the Include subfolders check box is selected. This ensures that everything in the account will be exported: Inbox, Calendar, Contacts, and Tasks. Choose Next.
Click Browse to select where to save the Outlook Data File (.pst). Enter a file name, and choose OK to continue.
If you are exporting to an existing Outlook Data File (.pst), under Options, specify what to do when exporting items that already exist in the file.
Choose Finish.

For more details, please refer to the official document: Export emails, contacts, and calendar items to Outlook using a .pst file - Microsoft Support.

This approach allows us to recover the mailbox data from the local cache and restore it to a new mailbox. If you encounter any issues during this process, please don’t hesitate to reach out for further assistance.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation](https://aka.ms/msftqanotifications)) to enable e-mail notifications if you want to receive the related email notification for this thread.

Axel C-FR 0

Hi Sharon,

Pretty sure we are Hybrid, as confirmed with the Microsoft's technician
I believe it's the second option, we create both Windows (Active Directory) / Mailbox from this admin center which I think it's called On-Premise ?
Here's the "get-user" command, I have hidden all sensitive information : sSecurityPrincipal : True SiloName : SamAccountName : $APD0A0-58S3BSEAHMP1 Sid : S-1-5-21-1475511947-1274405101-1044252824-23915641 SidHistory : {S-1-5-21-1475511947-1274405101-1044252824-23915641, S-1-5-21-1044957155-1279602233-3035652727-28605836,

                                    **S-1-5-21-1612083179-4102000699-3785483694-7053274}**
```   **UserPrincipalName                  : *******@domain.com***
   
   **BulkMailEnabled                    : False**
   
   **ResetPasswordOnNextLogon           : False**
   
   **CertificateSubject                 : {}**
   
   **RemotePowerShellEnabled            : True**
   
   **EXOModuleEnabled                   : True**
   
   **WindowsLiveID                      : *******@domain.com***
   
   **MicrosoftOnlineServicesID          : *******@domain.com***
   
   **NetID                              : 10037FFEAF398FB1**
   
   **IsCloudCacheProvisioningComplete   : False**
   
   **IsCloudCache                       : False**
   
   **CloudCacheProvider                 : 0**
   
   **CloudCacheAccountType              : None**
   
   **CloudCacheScope                    : 0**
   
   **CloudCacheRemoteEmailAddress       :** 
   
   **CloudCacheUserName                 :** 
   
   **IsCloudCacheBlocked                : False**
   
   **ConsumerNetID                      :** 
   
   **UserAccountControl                 : NormalAccount**
   
   **OrganizationalUnit                 : frap264a008.prod.outlook.com/Microsoft Exchange Hosted Organizations/novacap365.onmicrosoft.com**
   
   **IsLinked                           : False**
   
   **LinkedMasterAccount                :** 
   
   **LegalAgeGroup                      :** 
   
   **CreationType                       : None**
   
   **UserType                           : Member**
   
   **UserPersona                        : InternalMember**
   
   **ExternalDirectoryObjectId          : 7ce8a18e-44ba-4022-9f27-65092c922e86**
   
   **SKUAssigned                        : False**
   
   **IsSoftDeletedByRemove              : False**
   
   **IsSoftDeletedByDisable             : False**
   
   **WhenSoftDeleted                    :** 
   
   **PreviousRecipientTypeDetails       : UserMailbox**
   
   **UpgradeRequest                     : None**
   
   **UpgradeStatus                      : None**
   
   **UpgradeDetails                     :** 
   
   **UpgradeMessage                     :** 
   
   **UpgradeStage                       :** 
   
   **UpgradeStageTimeStamp              :** 
   
   **MailboxRegion                      :** 
   
   **MailboxRegionLastUpdateTime        :** 
   
   **MailboxRegionSuffix                : None**
   
   **MailboxProvisioningConstraint      :** 
   
   **MailboxProvisioningPreferences     : {}**
   
   **MailboxWorkloads                   : Mail, Calendar, Contacts, Substrate**
   
   **DefaultMailboxWorkloadsMask        : Mail, Calendar, Contacts, Substrate**
   
   **DesiredMailboxWorkloads            :** 
   
   **DesiredMailboxWorkloadsModified    :** 
   
   **DesiredMailboxWorkloadsGracePeriod :** 
   
   **LegacyExchangeDN                   : /o=ExchangeLabs/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=6463d0fcfea242b99a2ded6d7f168249-*USER* ET**
   
   **InPlaceHoldsRaw                    : {}**
   
   **MailboxRelease                     : None**
   
   **ArchiveRelease                     : None**
   
   **AccountDisabled                    : False**
   
   **AuthenticationPolicy               :** 
   
   **StsRefreshTokensValidFrom          : 25/02/2025 14:27:43**
   
   **IsInactiveMailbox                  : False**
   
   **MailboxLocations                   : {1;70fa4b3c-2678-41ea-9c6e-17554e173c24;ComponentShared;FRAP264.PROD.OUTLOOK.COM;7bd05c75-2203-4f2d-8002-78c0ee576601}**
   
   **InformationBarrierSegments         : {}**
   
   **WhenIBSegmentChanged               :** 
   
   **CanHaveCloudCache                  : False**
   
   **AdministrativeUnits                : {}**
   
   **AssistantName                      :** 
   
   **City                               : *USER***
   
   **Company                            : *USER***
   
   **CountryOrRegion                    : France**
   
   **Department                         : *HIDDEN INFORMATION***
   
   **DirectReports                      : {}**
   
   **DisplayName                        : *USER***
   
   **Fax                                :** 
   
   **FirstName                          : *USER***
   
   **GeoCoordinates                     :** 
   
   **HomePhone                          :** 
   
   **Initials                           :** 
   
   **IsDirSynced                        : *USER***
   
   **LastName                           : *USER***
   
   **Manager                            : *HIDDEN INFORMATION***
   
   **MobilePhone                        :** 
   
   **Notes                              :** 
   
   **Office                             : *HIDDEN INFORMATION***
   
   **OtherFax                           : {}**
   
   **OtherHomePhone                     : {}**
   
   **OtherTelephone                     : {}**
   
   **Pager                              :** 
   
   **Phone                              : *HIDDEN INFORMATION***
   
   **PhoneticDisplayName                :** 
   
   **PostalCode                         :** 
   
   **PostOfficeBox                      : {}**
   
   **RecipientType                      : MailUser**
   
   **RecipientTypeDetails               : MailUser**
   
   **SimpleDisplayName                  :** 
   
   **StateOrProvince                    :** 
   
   **StreetAddress                      :** 
   
   **Title                              : *HIDDEN INFORMATION***
   
   **UMDialPlan                         :** 
   
   **UMDtmfMap                          : {firstNameLastName:52384842384825, emailAddress:52384842384825, lastNameFirstName:38482552384842, reversedPhone:11511978433+}**
   
   **AllowUMCallsFromNonUsers           : SearchEnabled**
   
   **WebPage                            :** 
   
   **TelephoneAssistant                 :** 
   
   **WindowsEmailAddress                : *******@domain.com***
   
   **UMCallingLineIds                   : {}**
   
   **SeniorityIndex                     :** 
   
   **VoiceMailSettings                  : {}**
   
   **Identity                           : *USER***
   
   **Id                                 : *USER***
   
   **IsValid                            : True**
   
   **ExchangeVersion                    : 0.20 (15.0.0.0)**
   
   **Name                               : *USER***
   
   **DistinguishedName                  : CN=*USER*\, *USER*,OU=novacap365.onmicrosoft.com,OU=Microsoft Exchange Hosted Organizations,DC=FRAP264A008,DC=PROD,DC=OUTLOOK,DC=COM**
   
   **ObjectCategory                     : FRAP264A008.PROD.OUTLOOK.COM/Configuration/Schema/Person**
   
   **ObjectClass                        : {top, person, organizationalPerson, user}**
   
   **WhenChanged                        : 25/02/2025 14:34:35**
   
   **WhenCreated                        : 19/12/2024 10:14:44**
   
   **WhenChangedUTC                     : 25/02/2025 13:34:35**
   
   **WhenCreatedUTC                     : 19/12/2024 09:14:44**
   
   **ExchangeObjectId                   : 932c0b92-86bc-4701-ba99-f0eb5d5be2ae**
   
   **OrganizationalUnitRoot             : novacap365.onmicrosoft.com**
   
   **OrganizationId                     : FRAP264A008.PROD.OUTLOOK.COM/Microsoft Exchange Hosted Organizations/novacap365.onmicrosoft.com -** 
   
```sql
                                    **FRAP264A008.PROD.OUTLOOK.COM/ConfigurationUnits/novacap365.onmicrosoft.com/Configuration**
```   **Guid                               : 499f7df8-a79e-44c2-886c-42296557807a**
   
   **OriginatingServer                  : MR1P264A08DC002.FRAP264A008.PROD.OUTLOOK.COM**
   
   **ObjectState                        : Changed**
   
1. There was no .pst on her PC, only the .ost file, which is complete ! But we can't convert it fully, all web softwares give a free demo with 200Mo worth of data, which is nothing...

Sharon Zhao-MSFT 25,751 Reputation points Microsoft External Staff

2025-03-18T02:32:43.84+00:00

Hi @Axel C-FR,

Thanks for your reply.

Based on your answers, it appears that the affected user’s account and mailbox were created directly on-premises, and a license was assigned to her without prior migration.

This approach can lead to issues because assigning a license to an on-premises user creates a new mailbox in the cloud, which is separate from the on-premises mailbox. To avoid potential complications, the correct process is to first migrate the user’s mailbox from on-premises to Exchange Online and then assign the license.

For detailed guidance, please refer to: Exchange Server hybrid deployments | Microsoft Learn.

Regarding the cached data, since there is no existing .pst file on the user’s PC, we need to follow the steps I provided to export the data to a .pst file.

If the user can still open the Outlook client and view cached data (e.g., emails), exporting them to a .pst file is recommended. You can determine the export scope by checking the date of the oldest email in the cached data.

Let me know if you need further assistance.
Axel C-FR 0 Reputation points

2025-03-18T14:15:22.52+00:00

Hello,

It's weird because we always made accounts with this process and it's not the first time someone lost their licence but putting it back made nothing like this happen.

For the .pst, unfortunately, Outlook does not open anything either on software or web.

Here's the message from the web :

Yet she has the licence...

On the software, it just loads infinitely and finally says "Outlook couldn't configurate your account" so we can't even try to export anything.

On O365 console, it does indeed mention something about migrating the mailbox :

"This sender's on-premises mailbox has not been migrated to Exchange Online. The Exchange Online mailbox will be available when the migration is complete."

I didn't expect much but I tried to make a remote migration over Exchange but it fails and shows this :

"CouldNotDecryptPasswordException: Password for the user 'HIDDEN' could not be decrypted."

I've seen that deleting and retry was the way to go but still the same error...

Is it possible to create an Exchange Online mailbox and link it to her exisiting AD account ? Or a better way to migrate it ?
Sharon Zhao-MSFT 25,751 Reputation points Microsoft External Staff

2025-03-19T09:17:29.9233333+00:00
Hi @Axel C-FR,

Thanks for your reply.

If the affected user has a mailbox on-premises, the issue likely lies with the mailbox in Exchange Online, as no migration has been performed yet. To do this:

Move the affected user to a different Organizational Unit (OU) in Active Directory (AD) that is not synchronized with AAD.

Clear all data associated with this user in Exchange Online:

Log in to the Microsoft 365 Admin Center.

Navigate to "Users" > "Active Users."

Locate the user whose data needs to be cleared and click on their username to access the details page.

Click the "Delete User" button and confirm the deletion.

After deletion, the user's mailbox and associated data will be moved to the "Deleted Users" list and retained for 30 days.

Move the user back to the original OU and synchronize it from AD to AAD.

Perform the migration and assign the necessary license to verify if the mailbox works.

If the affected user does not have a mailbox on-premises:

Move the user to a different OU in AD that is not synchronized with AAD.

Clear all data associated with this user in Exchange Online.

Move the user back to the original OU and synchronize it from AD to AAD.

Assign the necessary license to the user and verify if mailbox works.

Please note the following:

For the first scenario, the database for the mailbox on-premises can be restored, but the online mailbox cannot.

For the second scenario, a completely new mailbox will be created, and no existing data can be restored.
Axel C-FR 0 Reputation points

2025-03-19T15:50:19.5433333+00:00
Hi,

I'm following the first scenario since she is on On-Premise.

I did everything as you noted but i'm blocking over the migration on Exchange Online, I have this error :

MissingExchangeGuidException: The user object for '****@domain.com' does not have a valid ExchangeGuid property and cannot be migrated.**

Her current msExchMailboxGuid in the Attribute Editor is : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 (hexadecimal)

I can't generate anything from : *Get-Mailbox "UPN" | fl guid because she is always missing from "PAXP264A08DC004.FRAP264A008.PROD.OUTLOOK.COM"

Do you know if this command can be useful ?

Set-ADUser -Identity "******@domain.com" -Replace @{msExchMailboxGuid=$newGuid.ToByteArray()}
Sharon Zhao-MSFT 25,751 Reputation points Microsoft External Staff

2025-03-20T08:05:09.14+00:00

Hi @Axel C-FR,

I attempted to run the command you provided, but I consistently encountered an error message indicating that the object could not be found, even though I confirmed that it should exist within the domain.

You may want to try running the command yourself to see if it works. If successful, please verify whether the mailbox can be created.

If the issue persists, creating a completely new account for this user might be an alternative.
Axel C-FR 0 Reputation points

2025-03-20T15:17:49.49+00:00

Hi Sharon,

It did generate a "new" Guid but it still didn't work for the migration, same error...

In the meantime today, Microsoft team reached out to me to grant me an additional role within Exchange Online admin center (Mail Recipient & Mail Recipient Creation) that is supposed to counter the :

"Access is denied.","type":"System.UnauthorizedAccessException","stacktrace":"","internalexception":{"message"

from my very first message on this Q&A.

There might be hours long synchronization before I can try to apply back some specific commands on Powershell... I keep you updated tomorrow if it leads to something.

Sorry for giving one answer max per day, I try my best to be available as soon as possible.
Sharon Zhao-MSFT 25,751 Reputation points Microsoft External Staff

2025-03-24T07:58:57.1166667+00:00

Hi @Axel C-FR,

Do you have any recent updates on this matter?

Feel free to share any progress or let us know if you need additional support.
Axel C-FR 0 Reputation points

2025-03-24T08:49:46.67+00:00

Hello @Sharon Zhao-MSFT ,

Apologies, I thought I gave an update on Friday...

Microsoft Support made another escalation to a different service, I should get something (hopefully) today.

They asked for this information :

**Get-MailboxLocation -User ****@domain.com -IncludePreviousPrimary

And unfortunately, there is a very high chance to not be able to restore former data, but atleast we still have the .ost file.

I will wait for their action before applying new ones, I keep you updated soon !
Sharon Zhao-MSFT 25,751 Reputation points Microsoft External Staff

2025-03-27T09:38:55.1633333+00:00

Hi @Axel C-FR,

This is a warm follow up to check the status of this case. Please feel free to share something here.
Axel C-FR 0 Reputation points

2025-03-27T13:23:21.21+00:00

Hi,Thank you for the follow up.

Ironically, this is where I get the most update because I am still pending for anything from the current Microsoft team !

I would love to continue some actions meanwhile...

Is there anything we could try from the "**Get-MailboxLocation -User ******@domain.com -IncludePreviousPrimary" command ?

Here are the results (unsure of what to censor but anything with "x" got some information) :

Id : 163bbxxxxxxxxxxxxxxxxxxxx

MailboxGuid : 70fa4b3c-xxxxxxxxxxxx

DatabaseLocation : FRAP264xxxxxxxxxxxxxxx

MailboxLocationType : PreviousPrimary

ContentSource : Unspecified

OwnerId : IMPACTER USER

ShardAddress :

TenantGuid : 163bbxxxxxxxxxxxxxxxxxxxxx

MailboxMoveBatchName :

MailboxMoveStatus : None

MailboxMoveFlags : None

RawExternalEmailAddress :

MigrationDryRun : False

OptInUser : False

IsMigratedConsumerMailbox : False

IsPremiumConsumerMailbox : False

SafeLinksEnabled : True

PrimaryMailboxSource : None

MailboxProvisioningConstraint :

SiloName :

Identity : 163bbxxxxxxxxxx

IsValid : True

ObjectState : New

I have tried to apply the MailboxGuid on msExchMailboxGuid but nothing happens...
Sharon Zhao-MSFT 25,751 Reputation points Microsoft External Staff

2025-03-31T08:52:39.8266667+00:00

Hi @Axel C-FR,

Just to recap - we've seen several users lose licenses, but only this one is having this particular problem. This points to something going on in the backend systems.

The best next step would be to waiting for the response of Microsoft's Exchange support team - they'll be able to dig into the technical details for you.
Axel C-FR 0 Reputation points

2025-04-03T13:56:21.4133333+00:00

Hi @Sharon Zhao-MSFT ,

I can finally say that this problem is no more.

We managed to get a meeting with a third technician, here are the steps as far as I can remember :

set-mailuser "****@domain.com" -RemoveDisabledArchive** > ok

set-user "****@domain.com" -PermanentlyClearPreviousMailboxInfo** > ok

We've also cleared out some Attribut from Active Directory regarding Archive and Guid but I'm not quite sure of the names, apologies...

Then we proceeded to do your previous steps about moving the user on non-synchronized OU, wait for everything to be "deleted" over Exchange and O365...

Put it back in a synchronized OU and restore the account from Entra/Azure AD (O365 doesn't recover everything according to him)

The mailbox finally appears as User Mailbox again !

User finally get her main address back, the only issue remaining is restoring former data with her previous .ost file.

The techinician also informed me about our account creation being risky as you already mentionned + someone may have manually edited user's Attribute Editor after the licence's loss...

Anyway, thank you for your time and efforts spent on this, it was not an easy one.

Best regards ! :D

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Can't revert from "Mail User" to "User Mailbox"

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