Vypress Messenger lets you instantly exchange text messages with other users across the Internet or any TCP/IP network. This utilitity is an excellent replacement for the "WinPopup" utility that comes with Windows. It is compatible with the SMB protocol, which allows messages to be received from Windows 95/98 WinPopup, Windows NT Messenger Service, Linux and Novell NetWare. There are message filtering options and a mail notification option that can work with IMAP4 servers.
More info:
hxxp://www.vypress.com/