Purging Mailboxes In Exchange 2003

I have recently demonstrated how to Purge a mailbox in Exchange 2007 but did not show anything for Exchange 2003. Here is what I do to purge mailboxes on Exchange 2003 server.

$list = gwmi -ComputerName "ex2k3srv" -Class Exchange_Mailbox -Namespace Root\MicrosoftExchangeV2 | ?{ $_.DateDiscoveredAbsentInDS -ne $null }
$list | %{ $_.Purge() }