Net Send

I want to know the proper way to send a Net Send message over a windows domain network. Everytime I try to send the message, is comes back with "The message alias could not be found on the network" when I know exactly what the user name, copmuter name, and even IP address is. I believe my syntax is correct: "net send computer_name message." What am I doing wrong?

The messenger service is not running on the target machine (that's nothing to do with MSN Messenger, by the way). It's disabled by default (certainly on any XP Pro installations I've done, anyway). You need to reenable it in services.msc.