you can also try to use:
smbclient -M NetBIOS name
This options allows you to send messages, using the "WinPopup" protocol, to another computer. Once a connection is established you then type your message, pressing ^D (control-D) to end.
this will work to send a message to :
- any NT4 / W2k station
- a W95/98 station with winpopup program running
- any samba client that is correctly configured ( see the message command parameter in the smb.conf for a description of how to handle incoming WinPopup messages in Samba).