To go on using the default Exchange Account for Exchange migration, grant the permissions required for Exchange migration to this account (see the next steps).
The account should have Read access to the source Active Directory.
To grant this permission to the account, complete the following steps:
The Source Exchange Account used by Migration Manager for Exchange agents needs the Full Control permission on each mailbox database involved in migration.
To grant the required permissions to the <User>, run the following cmdlets in Exchange Management Shell:
Get-MailboxDatabase | Add-ADPermission -User <User> -AccessRights GenericAll -ExtendedRights Receive-As
To verify that all permissions for the Source Exchange Account are set correctly, select any mailbox involved in the migration in the Migration Manager Console and check that the Source Exchange Account has Full Access permissions for the mailbox.
The account used by Migration Manager for Exchange agents needs the Mail Enabled Public Folders management role in the Exchange organization to be able to create mail-enabled public folders in case of two-way public folder synchronization.
To grant the required permission to the <User> (in our example, LA\QMM_Src_Ex), run the following cmdlet in Exchange Management Shell:
New-ManagementRoleAssignment -Role "Mail Enabled Public Folders" -User LA\QMM_Src_Ex