Editing Simple Mail Transfer Protocol (section)

=== Predecessors to SMTP ===
Various forms of one-to-one [[Instant messaging|electronic messaging]] were used in the 1960s. Users communicated using systems developed for specific [[mainframe computer]]s. As more computers were interconnected, especially in the U.S. Government's [[ARPANET]], standards were developed to permit exchange of messages between different operating systems. 

Mail on the ARPANET traces its roots to 1971: the Mail Box Protocol, which was not implemented,<ref>[http://www.multicians.org/thvv/mail-history.html The History of Electronic Mail] {{Webarchive|url=https://web.archive.org/web/20171202025034/http://www.multicians.org/thvv/mail-history.html |date=December 2, 2017 }}'', [[Tom Van Vleck]]: "''It is not clear this protocol was ever implemented''"''</ref> but is discussed in {{IETF RFC|196}}; and the [[SNDMSG]] program, which [[Ray Tomlinson]] of [[BBN Technologies|BBN]] adapted that year to send messages across two computers on the ARPANET.<ref>[//openmap.bbn.com/~tomlinso/ray/firstemailframe.html ''The First Network Email''], [[Ray Tomlinson]], BBN</ref><ref>Picture of "[//kingsmtp.com/the-first-email-computer/ The First Email Computer]" by Dan Murphy, a [[PDP-10]]</ref><ref>[http://www.opost.com/dlm/tenex/ Dan Murphy's TENEX and TOPS-20 Papers] {{webarchive |url=https://web.archive.org/web/20071118204016/http://www.opost.com/dlm/tenex/ |date=November 18, 2007 }}</ref> A further proposal for a Mail Protocol was made in RFC 524 in June 1973,<ref>{{IETF RFC|524}} – A Proposed Mail Protocol</ref> which was not implemented.<ref>{{Cite journal |last=Crocker |first=David H. |date=December 1977 |title=Framework and Functions of the "MS" Personal Message System |url=https://www.rand.org/content/dam/rand/pubs/reports/2007/R2134.pdf |journal=The RAND Corporation |access-date=April 17, 2022 |archive-date=May 13, 2022 |archive-url=https://web.archive.org/web/20220513083616/https://www.rand.org/content/dam/rand/pubs/reports/2007/R2134.pdf |url-status=live }}</ref>

The use of the [[File Transfer Protocol]] (FTP) for "network mail" on the ARPANET was proposed in RFC 469 in March 1973.<ref>{{IETF RFC|469}} – Network Mail Meeting Summary</ref> Through RFC 561, RFC 680, RFC 724, and finally RFC 733 in November 1977, a standardized framework for "electronic mail" using FTP mail servers on was developed.<ref name=":12">RFC 733, 21 November 1977, Standard for the Format of ARPA Network Text Message</ref><ref>{{Cite news |date=2023-05-20 |title=A history of e-mail: Collaboration, innovation and the birth of a system |url=https://www.washingtonpost.com/national/on-innovations/a-history-of-e-mail-collaboration-innovation-and-the-birth-of-a-system/2012/03/19/gIQAOeFEPS_story.html |access-date=2024-07-07 |work=Washington Post |language=en-US |issn=0190-8286}}</ref>

SMTP grew out of these standards developed during the 1970s. Ray Tomlinson discussed network mail among the [[International Network Working Group]] in ''INWG Protocol note 2'', written in September 1974.<ref name=":03">{{Cite journal |last=McKenzie |first=Alexander |date=2011 |title=INWG and the Conception of the Internet: An Eyewitness Account |journal=IEEE Annals of the History of Computing |volume=33 |issue=1 |pages=66–71 |doi=10.1109/MAHC.2011.9 |issn=1934-1547 |s2cid=206443072}}</ref> INWG discussed protocols for electronic mail in 1979,<ref>Barber, D., and J. Laws, "A Basic Mail Scheme for EIN," INWG 192, February 1979.</ref> which was referenced by [[Jon Postel]] in his early work on Internet email. Postel first proposed an Internet Message Protocol in 1979 as part of the [[Internet Experiment Note]] (IEN) series.<ref>{{Cite IETF|ien=85}}</ref><ref>{{Cite IETF|ien=113}}</ref><ref>{{Cite web |title=Internet Experiment Note Index |url=https://www.rfc-editor.org/ien/ien-index.html |access-date=2024-07-07 |website=www.rfc-editor.org}}</ref>