Exchange 2007 2010 powershell command to remove emails

If you have a situation where spammers have been using backscatter or other methods to send spam from your exchange server you may find thousands of emails in the Exchange queues.

You can use Exchange management console and under Toolbox open Queue Viewer to see this.

From the exchange powershell you can view the messages using the command

Get-message

This will return a list of messages in all queues
You will able to see common themes of the spam emails. Typically backscatter emails will have a fromaddress <> and you may see many permanent Delivery or Undelivered messages.
To specifically clear these from the queues without sending NDRs use the exchange powershell commands

Remove-Message -Server EX -Filter {FromAddress -like “<>”} -WithNDR $false
Remove-Message -Server EX -Filter {Subject -like “*Permanent*”} -WithNDR $false
Remove-Message -Server EX -Filter {Subject -like “*Undelivered*”} -WithNDR $false

Run Get-message again to check what is left in the queues, and run similar command to clear out the invalid emails.
To clear the entire submission queue at once you can stop the Microsoft Exchange Transport service and rename the folder

C:\Program Files\Microsoft\Exchange Server\V14\TransportRoles\data\Queue to Queue old.

Recreate a blank Queue folder and restart the Microsoft Exchange Transport service and it will recreate a clean database.