I was at a customer site where they had issues with moderated transport not working properly in Exchange 2010 and they had done a “cleanup” recently and deleted all accounts which were disabled. That gave me a clue as to why moderated transport wasn’t working ;) I had a look in AD and couldn’t find any of the system mailboxes which are created as part of Exchange 2010 setup. This has prompted me to write this post. So, here it goes…
Exchange 2010 creates three system mailboxes as part of the setup in the root domain. They are SystemMailbox{1f05a927-xxxx-xxxx-xxxx-xxxxxxxxxxxx}(where x is a random number/alphabet, the account is used for moderated transport), SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9} (used for discovery)and FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042 (used for federated email). The accounts are disabled in AD and they are not meant to be enabled or deleted. You can find the accounts in the “Users” OU by default.
You can also find the system mailboxes by running “Get-Mailbox –Arbitration” in Exchange Shell.
Now, what if someone accidently deletes the system mailboxes from Exchange, leaving the AD accounts in tact? The recovery is easy enough. As the AD accounts exist, all we need is to mailbox enable them with the –Arbitration switch. For example, run the command below.
Enable-Mailbox SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9} –Arbitration
What if someone deletes the disabled AD accounts as well? The fix is to run Setup.Com /PrepareAD from the Exchange 2010 DVD/ISO, as it is the AD preparation process (which is run as part of the 2010 setup) that creates the disabled system mailbox accounts in AD. Once the accounts are created, mailbox enable them using the command above.
The moral is to leave the disabled system accounts untouched 
Hi Rajith,
Good afternoon, I need your support and advice. In my active directory of my laboratory, disable the arbitration accounts, how do I do to re-create them again or if they should be disabled? Can you help me with this question please.
Awaiting your kind reply.
Greetings from Mexico.
Your server and friend.
Luis Gil.
I tried the Enable-Mailbox “SystemMailbox and seem to get a error stating the recipient, type is incorrect. any ideas?
Welcome to the Exchange Management Shell!
Full list of cmdlets: Get-Command
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Cmdlets that match a specific string: Help **
Get general help: Help
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Show full output for a command: | Format-List
Show quick reference guide: QuickRef
Tip of the day #59:
The special variable $_ represents the objects being passed from one cmdlet to another cmdlet in the pipeline. The $_ va
riable is automatically initiated by the Shell and is bound to the current pipeline object. You can access the propertie
s of the object assigned to the $_ variable as you would any other object. The following example shows how you can view
the Name property of each mailbox object that is passed through the pipeline:
Get-Mailbox | ForEach { $_.Name }
VERBOSE: Connecting to SVREX01.mch.corp.int.
VERBOSE: Connected to SVREX01.mch.corp.int.
[PS] C:\Windows\system32>Enable-Mailbox SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c} -Arbitration
A positional parameter cannot be found that accepts argument ‘1f05a927-a25f-44f6-8a0c-a38bbdb1c68c’.
+ CategoryInfo : InvalidArgument: (:) [Enable-Mailbox], ParameterBindingException
+ FullyQualifiedErrorId : PositionalParameterNotFound,Enable-Mailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Enable-Mailbox “SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c}” -Arbitration
The operation couldn’t be performed because object ‘SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c}’ couldn’t be
found on ‘MCHDC03.mch.corp.int’.
+ CategoryInfo : NotSpecified: (:) [Enable-Mailbox], ManagementObjectNotFoundException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=5baf4852-2147-4747-be2f-cb40288be380,TimeStamp=9/17/2015 7:47:
21 PM] [FailureCategory=Cmdlet-ManagementObjectNotFoundException] 199AF987,Microsoft.Exchange.Management.Recipient
Tasks.EnableMailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Enable-Mailbox “SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c}” -Arbitration | Set-ADServe
rSettings -ViewEntireForest:$true
The operation couldn’t be performed because object ‘SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c}’ couldn’t be
found on ‘MCHDC03.mch.corp.int’.
+ CategoryInfo : NotSpecified: (:) [Enable-Mailbox], ManagementObjectNotFoundException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=d13bbb4b-5872-414f-883e-a47fa3e0fefe,TimeStamp=9/17/2015 7:48:
19 PM] [FailureCategory=Cmdlet-ManagementObjectNotFoundException] 199AF987,Microsoft.Exchange.Management.Recipient
Tasks.EnableMailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Set-ADServerSettings -ViewEntireForest:$true
[PS] C:\Windows\system32>Enable-Mailbox “SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c}” -Arbitration
This task does not support recipients of this type. The specified recipient
corp.int/Users/SystemMailbox{1f05a927-a25f-44f6-8a0c-a38bbdb1c68c} is of type UserMailbox. Please make sure that this
recipient matches the required recipient type for this task.
+ CategoryInfo : InvalidArgument: (corp.int/Users/…c-a38bbdb1c68c}:RecipientIdParameter) [Enable-Mailbo
x], RecipientTaskException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=2391b3dc-f797-4979-a9a1-8a060ac45fb0,TimeStamp=9/17/2015 7:48:
41 PM] [FailureCategory=Cmdlet-RecipientTaskException] F13D71CB,Microsoft.Exchange.Management.RecipientTasks.Enabl
eMailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Enable-Mailbox SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c} -Arbitration
A positional parameter cannot be found that accepts argument ‘bb558c35-97f1-4cb9-8ff7-d53741dc928c’.
+ CategoryInfo : InvalidArgument: (:) [Enable-Mailbox], ParameterBindingException
+ FullyQualifiedErrorId : PositionalParameterNotFound,Enable-Mailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Enable-Mailbox “SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}” -Arbitration
This task does not support recipients of this type. The specified recipient
corp.int/Users/SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c} is of type UserMailbox. Please make sure that this
recipient matches the required recipient type for this task.
+ CategoryInfo : InvalidArgument: (corp.int/Users/…7-d53741dc928c}:RecipientIdParameter) [Enable-Mailbo
x], RecipientTaskException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=a1c3f3f0-9f41-482f-ad0f-72b8b6770f5a,TimeStamp=9/17/2015 7:50:
04 PM] [FailureCategory=Cmdlet-RecipientTaskException] 178673,Microsoft.Exchange.Management.RecipientTasks.EnableM
ailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Enable-Mailbox “FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042” -Arbitration
This task does not support recipients of this type. The specified recipient
corp.int/Users/FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042 is of type UserMailbox. Please make sure that this
recipient matches the required recipient type for this task.
+ CategoryInfo : InvalidArgument: (corp.int/Users/…bf-00a95fa1e042:RecipientIdParameter) [Enable-Mailbo
x], RecipientTaskException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=59114489-bfe0-4221-a126-28cdfe43d048,TimeStamp=9/17/2015 7:51:
09 PM] [FailureCategory=Cmdlet-RecipientTaskException] 6525BED2,Microsoft.Exchange.Management.RecipientTasks.Enabl
eMailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Enable-Mailbox “SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9}” -Arbitration
This task does not support recipients of this type. The specified recipient
corp.int/Users/SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9} is of type UserMailbox. Please make sure that this
recipient matches the required recipient type for this task.
+ CategoryInfo : InvalidArgument: (corp.int/Users/…8-e6c29d823ed9}:RecipientIdParameter) [Enable-Mailbo
x], RecipientTaskException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=a49b3c9d-7abe-4fd9-aea4-83a4287e4b0d,TimeStamp=9/17/2015 7:51:
51 PM] [FailureCategory=Cmdlet-RecipientTaskException] 708A5DE7,Microsoft.Exchange.Management.RecipientTasks.Enabl
eMailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>Set-ADServerSettings -ViewEntireForest:$true
[PS] C:\Windows\system32>Enable-Mailbox “SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9}” -Arbitration
This task does not support recipients of this type. The specified recipient
corp.int/Users/SystemMailbox{e0dc1c29-89c3-4034-b678-e6c29d823ed9} is of type UserMailbox. Please make sure that this
recipient matches the required recipient type for this task.
+ CategoryInfo : InvalidArgument: (corp.int/Users/…8-e6c29d823ed9}:RecipientIdParameter) [Enable-Mailbo
x], RecipientTaskException
+ FullyQualifiedErrorId : [Server=SVREX01,RequestId=6c34f3bf-c475-456d-aff9-67f0ddfc6c3f,TimeStamp=9/17/2015 8:21:
09 PM] [FailureCategory=Cmdlet-RecipientTaskException] 708A5DE7,Microsoft.Exchange.Management.RecipientTasks.Enabl
eMailbox
+ PSComputerName : svrex01.mch.corp.int
[PS] C:\Windows\system32>
Out of curiosity – are these exchange user objects movable to a different OU? or are they subjected to stay in the default USERS OU?
Hi Rajith,
I am trying to delete a Exchange 2010 mailbox DB after moving all three system mailboxes that you mentioned in your article; However, I have found one more system mailbox in the database that I am not able to move because the object is not found in AD. The system mailbox is “SystemMailbox{9b3a09cd-305f-4d58-8efb-84c130476569}”. This Exchange 2010 environment was upgraded from Exchange 2007, so I am not sure if this system mailbox is stuff left behind from this upgrade or it is an important component of Exchange 2010. So you know, I am not able to see this mailbox by running any of the Get-Mailbox -arbitration command, the only way I can see this mailbox is by running the command Get-MailboxDatabase mailboxdb1 | Get-MailboxStatistics. Is it okay to delete this mailbox? Can I move this mailbox to another database without deleting it?
Hi Rajith,
I noticed that my system mailboxes (FederatedEmail.4c1f4d8b-…, SystemMailbox{1f05a927-….}, SystemMailbox{e0dc1c29-…} and DescoverySearchMailbox {D919BA05-….})) was deleted so I wanted to re-create them using the setup.com /PrepareAD command from my exchange 2010 server.
It runs fine up until it does the “Configuring Microsoft Exchange Server” and then gives the following error:
“The well-known object entry with the GUID “29a962c2-91d6-4ab7-9e06-8728f8f842ea”, which is on the “CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=domain,DC=com” container object’s otherWellKnownObjects attribute, refers to a group “CN=Organization Management,OU=Microsoft Exchange Security Groups,DC=domain,DC=com” of the wrong group type. Either delete the well-known object entry, or promote the target object to “RoleGroup”.”.
I deleted the Organization Management group because I know that I can restore it using LDP.exe. But then when I run the setup again it wants me to delete the Organization Management object within the deleted objects. And I know if I do that I will not be able to recover it from the tombstone objects should something go wrong with the setup.
So can someone please confirm that they have tried this before and that it actually worked without messing up anything.
Or another solutions would be to let me know how to “promote the target object to “RoleGroup””
Looking forward to your expert advice.
Thanks in advance!!
Remember to run the following command first, if you are trying to view the arbitration mailboxes from a child domain:
Set-AdServerSettings -ViewEntireForest $True
Thanks for the tip David
Hi Rajith,
Great article.Could you please clarify my query if you had a time? Why Exchange 2010 does not have independent System mailbox than Exchange 2003?
Thanks in Advance
Hi MK,
The architecture is completely different in 2010.
Thanks for useful article. this one really helped me to get the system mailbox created in exchange.
Thanks Solution Finder ;)