Mailbox move Exchange 2010: Post-move cleanup failed. The operation will try again in 30 seconds

If in the log (once mailbox move completed) you have below error and possibly you are at SP2 or less then you need to upgrade to SP3 or  run below script to delete old mailbox...

Date & Time [Server] Move has completed and final cleanup has started.
Date & Time [Server] Source mailbox 'Primary (Mailbox GUID)' was successfully cleaned up after the move.
Date & Time [Server] Target mailbox 'Primary (Mailbox GUID)' was successfully reset after the move.
Date & Time [Server] Post-move cleanup failed. The operation will try again in 30 seconds (1/6).
Date & Time [Server] Post-move cleanup failed. The operation will try again in 30 seconds (2/6).
Date & Time [Server] Post-move cleanup failed. The operation will try again in 30 seconds (3/6).
Date & Time [Server] Post-move cleanup failed. The operation will try again in 30 seconds (4/6).
Date & Time [Server] Post-move cleanup failed. The operation will try again in 30 seconds (5/6).
Date & Time [Server] Request is complete.

The resource mailbox is still present, because there has been a Soft Delete. We can remove the source (old mailbox) with below PowerShell script where you replace the DBNAME with yours:

$Mailboxes = Get-MailboxStatistics –Database DBNAME| where {$_.DisconnectReason -eq “SoftDeleted”}
$Mailboxes | foreach {Remove-StoreMailbox -Database $_.database -Identity $_.mailboxguid -MailboxState SoftDeleted}

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