In 1980, Jon Postel published RFC 772 which proposed the Mail Transfer Protocol as a replacement of the use of the File Transfer Protocol (FTP) for mail. Development work continued throughout the 1970s, until the ARPANET transitioned into the modern Internet around 1980. įurther implementations include FTP Mail and Mail Protocol, both from 1973. Fewer than 50 hosts were connected to the ARPANET at this time. SMTP traces its roots to two implementations described in 1971: the Mail Box Protocol, whose implementation has been disputed, but is discussed in RFC 196 and other RFCs, and the SNDMSG program, which, according to RFC 2235, Ray Tomlinson of BBN invented for TENEX computers to send mail messages across the ARPANET. SMTP grew out of these standards developed during the 1970s. Government's ARPANET, standards were developed to permit exchange of messages between different operating systems. As more computers were interconnected, especially in the U.S.
Users communicated using systems developed for specific mainframe computers.
Various forms of one-to-one electronic messaging were used in the 1960s. 6.7.2 SMTP MTA Strict Transport Security.4.1 Outgoing mail server access restrictions.