RFC 1168 (rfc1168) - Page 2 of 18
Intermail and Commercial Mail Relay services
Alternative Format: Original Text Document
RFC 1168 Intermail and Commercial Mail Relay Services July 1990 The Internet is an interconnected system of networks using the SMTP mail protocol, which includes the ARPANET, MILNET, NSFNET, and about 700 other networks; mail relays allow the exchange of mail with BITNET, CSNET, and the UUCP networks as well. To the users, this Internet looks like one large mail system with at least 100,000 computers and at least 400,000 users. Figure 1 illustrates the path of a message sent by a user on one Internet host to a user on another Internet host. For more details on the Internet and connected networks (see Appendix A). As commercial mail systems came into popular use, it became clear that a mail link between the Internet and the commercial mail systems was necessary (see Appendix B). More and more commercial and research entities needed to communicate with the Internet research community, and many of these organizations (for one reason or another) were inappropriate candidates for Internet sites. The Intermail and CMR services allow these groups to communicate with Internet users by purchasing electronic mail services from commercial companies. INTERMAIL Intermail is an experimental mail forwarding system that allows users to send electronic mail across mail system boundaries. The use of Intermail is nearly transparent, in that users on each system are able to use their usual mail programs to prepare, send, and receive messages. No modifications to any of the mail programs on any of the systems are required. However, users must put some extra addressing information at the beginning of the body of their messages. <<< Figure 1 - Internet to Internet Mail >>> The earliest version of Intermail was developed in 1981, by Jon Postel, Danny Cohen, Lee Richardson, and Joel Goldberg [1]. It ran on the TOPS-20 operating system and was used to forward VLSI chip specifications for the MOSIS project between the ARPANET and the Telemail system. The original addressing model used in this system was called "Source Route Forwarding". It was developed to handle situations in which a message might travel multiple hops before reaching its destination. Later, in 1983, Annette DeSchon converted Intermail into a more general-purpose mail-forwarding system, supporting forwarding between the Internet mail system and three commercial mail systems: Telemail, MCI Mail, and Dialcom [3,4]. Westine, DeSchon, Postel & Ward
