>>It's not MSN it's built-in Windows Messenger Service. In particular, NET SEND uses it to send messages between Pc's.
>
>That's what I meant. The Windows MSN Messenger. Whenever it's running, those messages are coming in. If it's not running, they're not.

Than we're talking about two different types of spam. The one with Windows Messenger Service doesn't require presence of MSN Messenger at all.