How to purge deleted items from recoverable items in Exchange

If you want to delete all the deleted items in a mailbox that are still recoverable you can use this command:

Search-Mailbox -Identity "David Cooper" -SearchDumpsterOnly -TargetMailbox "Discovery Search Mailbox" -TargetFolder "david.cooper-RecoverableItems" -DeleteContent

If you do not wish to make a copy of the deleted items first to the Discovery Mailbox, and just delete them, use this command:

Search-Mailbox -Identity "David Cooper" -SearchDumpsterOnly -DeleteContent