Cannot Open Microsoft System Attendant Mailbox Error During Mailbox Move

MS Exchange

A local mailbox move in Exchange 2013 fails with the error that the System Attendant Mailbox cannot be opened. I thought System Attendant was a thing of the past!


Exchange 2013 doesn’t have system attendant mailbox or even the System Attendant service (mad.exe).


But, the error clearly mentions about the failure to open the attendant mailbox. Though System Attendant mailbox & service have been removed from Exchange 2013, the object is still present in the configuration partition.


But, that was not the cause of the error. Exchange 2013 has a new arbitration mailbox “Migration.8f3e7716-2011-43e4-96b1-aba62d229136” with a display name “Microsoft Exchange Migration”.


In my case, the database hosting this arbitration mailbox was dismounted for some reason. I mounted the database back and the move was successful. In short, this arbitration mailbox is required for successful mailbox moves.

If you have deleted it by mistake or it doesn’t exist in your Exchange (for whatever reason), you can always re-create the AD account by running Setup.exe/PrepareAD. Once the account is created, configure a mailbox for the account by running the command below.

Enable-Mailbox –Arbitration –identity “Migration.8f3e7716-2011-43e4-96b1-aba62d229136”

Please let me know if you have any questions in the comments section.

Other Popular Articles

MS Exchange

Keep Track Of Exchange 2013 Database Failovers

MS Exchange

Playing With Exchange 2013 Performance Logs

MS Exchange

Tackle .Net Framework 4.6.1 On Exchange Servers

  1. Hi Rajith, am having same issue, arbitration mailboxes fine can even move them, but moving any mailbox get error:
    Cannot open mailbox /o=MyFirm/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=Exchange2007/cn=Microsoft System Attendant. Trying to enable-mailbox -Arbitration -Identity “Migration*” get following error:
    This task does not support recipients of this type. The specified recipient is of type UserMailbox. Please make sure that
    this recipient matches the required recipient type for this task.
    BTW moving from 2013 to 2019.

  2. In my case, I received the same error when moving a single mailbox into a new database meant to receive *just* that mailbox (my CIO’s. He fools with stuff often and breaks it. Hence, with his own database, he’ll only take himself out). Moving a 10.873GB mailbox generated more logging than the log drive for this database was sized for, so the migration stopped, giving the System Attendant error the OP mentioned. Dismounting and remounting the database fails, so the only elegant solution was to up the size of the log drive. In this case, I arbitrarily chose 20GB. Remounting was immediately successful, and the migration resumed on its own. All told, just shy 16.4 GB of logging was generated to move this box, so one suggestion is to turn on circular logging, if only during migrations that are expected to generate a bunch of logging.

  3. I am able to do mailbox moves, no problem. I get the error when I try and create a Resource mailbox.

    Here are the 5 arbitration mailboxes I have:

    All mailbox databases are mounted and DAG copy is healthy. I can create a user mailbox, but not a Resource mailbox. Very strange. This is a new build Active Directory and Exchange 2013 CU8. I don’t have this problem in any of the other environments I manage (15 total).

  4. Arbitration mailbox by default disabled. Why these are disabled account in AD.

    If I am trying to enabled this mailbox, It showing error through exchange shel”task does not support recipientss of this type”

    If I am trying to enable through DSA.msc, It showing unable to update the password.

    These account should be disabled or enabled.

  5. Hello Rajith,

    cool website here ;-).

    We have the same exact problem from Joel. All five arbitration boxes are available.
    Is the problem from Joel resolved yet?

    Thanks in advance.


  6. Get-Mailbox -Arbitration lists nothing in my Ex2013 environment. Neither is there any Exchange Migration acccount listed in AD. Can this account only be created by running Setup.exe/PrepareAD. What is the impact of this? Thx

      • Hi Joel,

        Please email me using the contact form. Or you can have the image uploaded in a public domain like pastebin dot com

    • For me the solution below worked, as I had found I indeed had a quarantined mailbox via the event log in Windows Server, still not sure what mailbox it was:

      Resetting a quarantined mailbox
      It is possible to reset a quarantined mailbox by deleting the quarantine registry key for that mailbox located at:

      HKLM\SYSTEM\CCS\Services\MSexchangeIS\Servername\Private-dbguid\Quarantined Mailboxes\ {Mailbox guid}.

      The database then has to be dismounted and remounted or the IS service restarted for the reset to take effect immediately. Unless the underlying issue is not resolved, the mailbox could crash the store and become quarantined again.

      I dismounted the database and remounted. Voila, no more error message when going into Migration in EAC.

  7. Hi Rajith,

    I’ve recently installed Exchange 2013… mind you i have an existing 2007 environment where all our users connect to. I have successfully migrated 10 mailboxes from 2007 to 2013 with no issues… Today I decide to take a look at the resources tab on exchange 2013. I show all of them in there but when i click on any them i receive the following error:

    Cannot open mailobx /o=Firm/ou=Exchange Administrative Group (FYDIBOHF13SL!!)/cn=Configuration/cn=Servers/cn=Exchange2007Firm/cn=Microsoft System Attendant.

    Any reason why?

    • Hi Joey,

      As explained in the article, do you have all five arbitration mailboxes? Run Get-Mailbox -Arbitration in 2013 Shell and paste the output here to help you better.


      • Thanks for the quick response Rajith. BTW awesome website!

        [PS] C:\Windows\system32>Get-Mailbox -Arbitration

        Name Alias ServerName ProhibitSendQuota
        —- —– ———- —————–
        SystemMailbox{1f05a927… SystemMailbox{1f0… ex2013firm Unlimited
        SystemMailbox{e0dc1c29… SystemMailbox{e0d… ex2013firm Unlimited
        FederatedEmail.4c1f4d8… FederatedEmail.4c… ex2013firm 1 MB (1,048,576 bytes)
        SystemMailbox{bb558c35… SystemMailbox{bb5… ex2013firm Unlimited
        Migration.8f3e7716-201… Migration.8f3e771… ex2013firm 300 MB (314,572,800 bytes)

        • That looks fine to me Joel.

          When do you get the error? When you try to move a mailbox? Between 2013 or with legacy?
          Bit more info please.

          • Well the resources are a bit different right. When I click on Recipients—Resources— and I try to click one the conference I get that error.

            Cannot open mailbox /o=MyFirm/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Configuration/cn=Servers/cn=Exchange2007/cn=Microsoft System Attendant.

  8. Also, keep in mind the logging for the Database where the migration mailbox resides. if you are doing a lot of moves, the logs will start to increase. so Either plan your moves in between backups to flush the transaction logs of the DB that holds the migration mailbox, or set Circular logging on the DB that holds the migration mailbox


Leave a Comment

Disable Windows Copilot Using Intune

Windows Copilot is Microsoft’s take on making life easier for Windows users using the power of AI. This article explains how to disable the feature using Intune, if your organization is not ready yet to walk into the AI world.

Disable Windows Copilot Using Intune

We need to create a Configuration Profile for Windows devices in the Intune portal to disable Windows Copilot. Below are the steps that we need to create the profile.

Launch the Intune Portal and login as a Global Admin or Intune Admin.

Navigate to Devices -> Windows -> Configuration Profiles.

Windows Configuration Profile Intune

Click on Create -> New Policy.

Select Windows 10 & later as the platform and Settings Catalog as the profile type & click on the Create button.

Settings Catalog Intune CoPilot

Give the policy a meaningful name & description and click Next.

Policy Name Disable CoPilot

Within the configuration settings, click on the Add Settings option.

Add Settings Disable CoPilot

Search for ‘copilot’, Windows AI will come up as the category. Click on Windows AI and the Turn off Copilot in Windows (User) setting will come up. Check the box and click Next.

Turn off CoPilot Setting Intune
Turn off CoPilot Setting Intune Summary 1

Specify scope tags if required and click Next.

Select tags CoPilot Intune

Select who this policy should apply to in the Assignments section. I have selected to add all users. If you want to test the setting, you can create a test group and select that group here.

Similarly, you can also exclude certain group from disabling AI (say IT team) if required.

Add all users disable copilot intune

A summary of selected settings will be displayed. Click on the Create button to setup the policy to disable Windows Copilot.

Create configuration policy disable CoPilot Intune 1

Wait for the replication to complete in the cloud backend and login to your machine. Your chatty Copilot should now be disabled.

Disable Windows Copilot On Windows 11 Pro

Follow the steps below to disable Copilot on a personal Windows 11 Pro machine (say your own laptop).

Search for ‘group’ in Windows 11 and click on Edit Group Policy option.

Group Policy Windows 11 Disable Copilot

Navigate to User Configuration -> Administrative Templates -> Windows Components -> Windows Copilot.

Windows Copilot GPO setting

Double click on Turn off Windows Copilot setting on the right pane.

Select Enabled and click OK.

Turn off copilot gpo Windows 11 Pro 1

Close the Group Policy Editor. This will disable Windows Copilot on a Windows 11 Pro machine.


We have learned to disable Windows Copilot using Intune and Group Policy on Windows 11 machines.

Please let me know if you have any questions in the comments section.

Promote Windows Server 2025 To Domain Controller

Domain controllers are the backbone of any Active Directory domains in the Microsoft world. Any Windows server can be promoted to be a domain controller. In this article, we will go through the steps of promoting a Windows 2025 Server to be a domain controller.

Windows Server 2025

The latest version of the server operating system has been named Windows Server 2025. You can start with a 2025 Server & create an AD domain or you can promote a member server that is already a part of a domain.

The Windows Server 2025 needs to be installed on a machine before it can be promoted to be a domain controller.

Promote Windows Server 2025 To Domain Controller

If you have been working with Windows servers long enough, everything starts with the Server Manager app. Promoting a server to a domain controller is no different.

Launch ‘Server Manager’ & click on Add roles and features.

Windows 2025 Server Manager

You land on the summary page that explains what is required to run this wizard successfully. Click Next.

Windows Server 2025 Add Remove Roles

Select Role-based or Feature-based installation and click Next.

Windows Server 2025 Role Based Install

Select the server that needs to be promoted and click Next.

Windows Server 2025 Destination Server

Select Active Directory Domain Services (second option) and click on Add Features.

Windows Server 2025 AD Domain Services

Go with the default options for features that need to be installed.

Windows Server 2025 AD Domain Services Features

A summary of AD DS pops up next, click next to continue.

Windows Server 2025 AD DS

Select Restart the server automatically if required and click Install.

Windows Server 2025 AD Restart Server

You get to keep an eye on the progress of the installation.

Windows Server 2025 AD Install Progress

Once the role has been installed, you will find an exclamation mark on the top right corner of the Server Manager. Click on that and select Promote this server to be a domain controller.

Windows Server 2025 AD Install Continue

You get an error straight away (which you have never seen before) – Error determining whether the target server is already a domain controller. Role change is in progress or this computer needs a restart.

Windows Server 2025 Domain Controller Setup Error

We never needed to restart the server after installing the role in the DC promotion process. Given that it is an insider build of Server 2025, I am hoping that this will get fixed before the public release.

Restart the server, launch Server Manager and click on the Promote this server to be a domain controller option again.

Windows Server 2025 AD Install Continue 1

I am setting up a brand new AD forest and hence I select the third option (Add a new forest) and enter my root domain name.

Windows Server 2025 Add a forest

Next window brings the option to set your forest & domain functional level and the DSRM password. In the insider build, it shows what looks like a variable (the Windows server version on which the you are working).

Windows Server 2025 Forest Functional Level

You can leave the default options in the DNS options wizard and click next.

Windows Server 2025 DNS Options

Enter the netbios name of the domain in the next window and click next.

Windows Server 2025 Netbios Domain Name

You can stick with the default paths for the AD database, log & sysvol folder or pick a location of your choice.

Windows Server 2025 AD Paths

Review the selections that you have made so far and click next.

Windows Server 2025 Options Review

Wait for the green check mark on the prerequisites page and click next.

Windows Server 2025 Pre reqs Check

Click Install in the final window & wait for the magic to happen. Once the machine gets restarted (which it will do automatically), you will have a brand new domain controller based on Windows Server 2025.

Windows Server 2025 AD Snap In


Promoting a Server 2025 to a domain controller follows pretty much the same steps as previous operating systems. The Insider build has few errors that needs to be fixed, but hey, it is an insider build!

Please let me know if you have any questions in the comments section.

Install Windows Server 2025 – Full Guide

Microsoft has released an insider preview of it’s next server operating system named Windows Server 2025. We will have a look at the installation steps involved in setting up a 2025 server.

Windows Server 2025

Microsoft has gone with the same look and feel of Windows 11 operating system in it’s current server operating system – Windows Server 2025. As the product is in insider preview, there might be slight changes before it hits the public shelves.

It is refreshing to see a ‘modern’ feel in the installation process of a server operating system. Gone are the days where the installation of a consumer based OS felt much better compared to it’s server counterpart.

Installing Windows Server 2025

Let’s take a look at the steps involved in setting up a Windows Server 2025 machine. First step is to download the ISO from the Windows Insider portal.

Next step is to boot the virtual / physical machine from the ISO which will kick off the installation of Server 2025.

First option to select is the language settings. Pick the one based which relates to you and click next.

Windows Server 2025 language settings

Select the keyboard settings in the next screen and click next.

Windows Server 2025 keyboard

You get the option to select whether you want to Install Windows Server or Repair the installation. The bottom left corner also has the option to go to the previous version of setup.

Windows Server 2025 setup option

You are asked to enter the product key, which is available in the Windows Insider portal.

Windows Server 2025 product key

Next option to choose is the type of image you want to install – Windows 2025 core or full blown desktop experience.

Windows Server 2025 Desktop

You need to agree to the licensing terms to move forward in the next step.

Windows Server 2025 Agreement License

Select the partition on which the server OS should be installed and click next. You also have the option to slice the partitions the way you see fit in the same screen.

Windows Server 2025 Disk Partitions

The Ready to Install window comes up, click the install button.

Windows Server 2025 Install 1

Installation of Server 2025 is underway and you get to see the progress.

Windows Server 2025 Install Progress

Once the installation is complete, you need to enter an administrator password of your choice to finalize the setup.

Windows Server 2025 Password

And there you go! You see a Windows 11 login screen staring at you ;-)

Windows Server 2025 Login Screen

After logging in, you get to set the options around sending diagnostic data to Microsoft, which I always set as ‘required only’.

Windows Server 2025 Diagnostic Data

The Windows Server 2025 desktop looks similar, doesn’t it? ;-)

Windows Server 2025 Desktop Feel scaled

Now that the server is up and running, you can promote it to be a domain controller.


The Windows Server 2025 has the same look and feel as a Windows 11 operating system. The installation options also provide that modern ‘feel’ and makes it a bit soothing to the eyes!

Please let me know if you have any questions in the comments section.