Group Net Send does not seem to work on my computer, why?
Group Net Send uses the Microsoft Messaging Service to send and receive its messages. This service must be running on the machine that sends the message AND the message that you send it to. If you installed Windows XP SP2, it will disable this service from running. This service can be located in the Services area of the Control Panel or Administrative Tools. Once the Windows Service has started on both computers you can use the computername or username to send the message.
As a test, add your OWN computername to the list of names to send messages to. Try sending a message to yourself.
If you are using Windows NT, please ensure you are on the latest Service Pack. We have had some reports of Group Net Send not working on earlier versions of Windows NT.
For Net Send Lite, you should use the From Who option and check Computername. This setting can be found on the Options screen in the latest version of Net Send Lite.
Another note: Try restarting the Messenger service via Right-Click Restart inside of the Services Control Panel. Then also restart the service name "TCP/IP NetBIOS Helper". This is the service that does the name resolution on your username.
For more information please Read this FAQ regarding this topic.