I have written a perl application using the Win32::GUI module that does this. Our Security department here at the college needed a way to send out messages to all the administrative offices such as severe weather alerts, power outtages, etc. Just recently there was a bank robbery just a few blocks from the campus. This application is password protected to prevent malicious use in case it ever got into the wrong hands.

This application will allow for 'canned' messages to be saved as well in case they ever need to use a recurring message. It still neeeds some tweeking but it's a lot easier than the net send command.

I don't think everyone has a malicious intent for an application like this.