ABSTRACT
Historically, e-mail on PC-based systems has been done using proprietary LAN-based systems (e.g., cc:Mail or MS Mail). Most of these systems have some scheme for linking multiple LANs (connected by WAN or dial-up links) together into an “enterprise” mail system (e.g., Microsoft’s Message Transfer Agent for MS Mail). They also typically have “Internet gateways” (e.g., Microsoft’s SMTP Gateway for MS Mail) available to allow their users to exchange mail with direct users of Internet mail. Furthermore, if two such proprietary LAN-based e-mail systems both have Internet mail gateways (whether the two LAN-based systems are from the same or from different vendors), it is possible for users of one LAN-based mail system to exchange mail with users of the other LAN-based mail system, using the Internet as a “backbone.”
