CMailServer, a small and easy to administer mail server with built-in web mail. It enables you to send and receive emails across the Internet or within your LAN. CMailServer provides basic features and lacks almost all advanced options usually offered by commercial mail servers, but offers unlimited users. If you are looking for basic server features that include web mail access (requires IIS) and is easy to use, give it a try. The unlimited user license makes it an inexpensive solution.