I was upgrading an hybrid Exchange environment for a customer and started to install the first Exchange 2016 server when i received the below error.

Initial Install Error

I hadn’t seen this error before but after some research it looked to be an issue with Arbitration Mailboxes being corrupt. So I decided to look at the state of ther Arbitration Mailboxes in Exchange 2010 by running

Get-Mailbox -Arbitration | select name,servername,database

I received the below output.

Sub Domain Arbitration Mailboxes

Strange, this doesn’t appear to show any errors, but neither does it show all the default Arbitration Mailboxes in an Exchange 2010 environment. At this point I remembered Exchange is installed in a subdomain of the AD DS Forest. So i changed the scope by running the below command and re ran the above.

Set-ADServerSettings -ViewEntireForest:$true

All arbitration mailboxes_LI

Now we can see that two of the Arbitration Mailboxes look to be corrupt and do not reside in a Mailbox Database. When checking on the Exchange Servers in the environment, the server listed here does not even exist!

Exchange Servers_LI

Now I have been able to identify the Arbitration Mailboxes causing a problem, I can disable them in Exchange and re-enable them. I started with the FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042 mailbox.

Disable-Mailbox “FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042” -Arbitration

Enable-Mailbox “FederatedEmail.4c1f4d8b-8179-4148-93bf-00a95fa1e042” -Arbitration

Upon initial run of the Enable command I received an error stating that the Active Directory account must be logon-disabled. I located the AD account in the root domain and disabled it. It was successful second time round.

Enable Federated Mailbox

Next I tried the SystemMailbox{1f05a927-03c2-4143-a3e2-c37ec8006a64}. Upon initial try I was unable to disable the mailbox and had to include an extra switch for the command to be successful.

Disable-Mailbox “SystemMailbox{1f05a927-03c2-4143-a3e2-c37ec8006a64}” -Arbitration -DisableLastArbitrationMailboxAllowed

Enable-Mailbox “SystemMailbox{1f05a927-03c2-4143-a3e2-c37ec8006a64} ” -Arbitration

Enable System Mailbox

Now if we check the state of the Arbitration Mailboxes once more, we can see they are no longer corrupt.

All arbitration mailboxes - Final

Once this is OK, i was able to rerun the Exchange Install and it proceeded past the error i was receiving.


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