Summary: About arbitration mailboxes in Exchange 2013 and how to re-create them.
Exchange 2013 comes with five system mailboxes known as arbitration mailboxes. Arbitration mailboxes are used for storing different types of system data and for managing messaging approval workflow. The below chart lists each type of arbitration mailbox and their responsibilities.
This mailbox stores data used to maintain federation between different Exchange organizations. This includes Rights Management Services, cross-premises mail-flow monitoring probes and responses, notifications, online archives, messaging records management, and cross-premises free/busy information.
SystemMailbox{1f05a927-XXXX-XXXX-XXXX-XXXXXXXXXXXX} (for example, SystemMailbox{1f05a927-9350-4efe-a823-5529c2d64109}; most of the mailbox name is unique to your organization)
Microsoft Exchange Approval Assistant
{}
This mailbox is provisioned for use by the Exchange approval framework for recipient moderation and auto group approval requests.
Migration.8f3e7716-2011-43e4-96b1-aba62d229136
Microsoft Exchange Migration
{OrganizationCapabilityManagement}
Stores data for the Exchange migration service to use when moving mailboxes in batches.
Provisioned for use by e-Discovery feature, which is used by compliance officers to locate messages that match specified selection criteria. This mailbox is also used by Unified Messaging for storing UM console attending files and other information.
This is known as an organization mailbox. It is used for creating offline address books (OABs). To load-balance OAB generation across your organization, including across geographically separate sites, you can create additional organization mailboxes.
If you need to re-create one of more of these arbitration mailboxes, see the instructions that follow.
What you should know before you begin
Estimated time to complete: 10 minutes per procedure.
You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Recipient Provisioning Permissions" section in the Recipients Permissions topic.
When finished, if you run the command $OABMBX = Get-Mailbox "SystemMailbox{bb558c35-97f1-4cb9-8ff7-d53741dc928c}" -Arbitration (Get-ADUser $OABMBX.SamAccountName -Properties *).msExchCapabilityIdentifiers you will see that 46, 47, and 51 are missing. Run the following command to add all of the capabilities back:
To verify that you have successfully re-created the arbitration mailbox, use the Get-Mailbox cmdlet with the Arbitration switch to retrieve system mailboxes.
This module examines how Microsoft 365 supports data governance by enabling organizations to archive content by using archive mailboxes and restore deleted data in Exchange Online and SharePoint Online.