Electronic Mail
Sixty years ago, the business world operated at the pace of paper. Executives dictated their letters to their secretaries, who mastered the delicate art of shorthand before transcribing on typewriters, with that characteristic sound of keys striking the ink ribbon. Each message followed the rigid protocol of the official letterhead, codified courtesy formulas, and carbon copies for the archives. The mail then departed into the maze of the postal system.
As early as 1965, at MIT, Tom Van Vleck and Noel Morris tinkered with something unprecedented. On their laboratory’s time-sharing computer, they created a command called mail that allowed users to send messages stored in virtual mailboxes. The idea seemed trivial, but it already disrupted habits: no more need to physically move to transmit information, no more waiting, no more paper lying around.
Six years later, Ray Tomlinson accomplished the gesture that would change the history of human communication. This engineer at Bolt Beranek and Newman was working on ARPANET when he decided to adapt the sndmsg program to enable distant computers to communicate. He needed a way to distinguish the user from their machine, and it was almost by chance that he chose the @ symbol on his keyboard. This at sign, which accountants used to note “so many units at such a price,” bridged the gap between digital identity and the computer’s physical address. First message sent: “QWERTYUIOP” or something close. Tomlinson forgot the exact content, which shows he didn’t grasp the magnitude of his invention.
The contagion effect was immediate on ARPANET. Researchers and engineers discovered they could exchange without time or geographic constraints, and instantaneously. No more interrupted phone calls, no more letters taking a week to cross the country. Larry Roberts, who directed ARPA’s IPTO office, quickly understood the value of this technology. In 1972, he developed rd, a program that sorted and classified received messages. Barry Wessler improved it with nrd, and John Vittal took a decisive step in 1974 with MSG, which introduced “reply” and “forward” functions. Electronic mail ceased being a simple transmission system to become a true conversation tool.
Technology followed usage. Early message formats resembled makeshift solutions, with each system having its own conventions. RFC 561 of 1973 attempted to impose order by defining the From:, Subject:, and Date: fields. This standardization work continued laboriously until RFC 822 of 1982, which defined the foundations of the format still used today.
Jon Postel, a legendary figure of the Internet, tackled the problem of message transport. Early systems used FTP, but this protocol proved unsuitable for the growing volume of exchanges. He designed Simple Mail Transfer Protocol in 1982, a protocol of elegant simplicity that would span decades without aging. This exceptional longevity in the computing universe testifies to the quality of its design.
The 1980s saw a proliferation of incompatible networks. UUCP connected UNIX machines, CSnet served universities, Bitnet linked computing centers. Each network had its addressing rules, conventions, and limitations. System administrators juggled with bewildering addresses like ihnp4!ucbvax!user@host, veritable computer roadmaps that specified the exact path of the message. This complexity disappeared with the arrival of the domain name system in 1984 and MX records two years later. The user@domain.com address then established itself as the universal standard.
In 1981, Eric Allman developed sendmail, and Dave Crocker created MMDF in 1982. These sophisticated programs handled message routing between heterogeneous systems, but ran into a limitation: electronic mail could only transport ASCII text. Impossible to send a photo, formatted document, or presentation. Users worked around the problem by encoding binary files, but the manipulation was tricky. The MIME standard of 1992 finally freed electronic mail from these constraints by allowing multimedia content. This evolution transformed messaging into a true professional exchange platform.
From a few hundred pioneer users on ARPANET, electronic mail now brings together more than 4.37 billion people. This massive adoption is explained by remarkably judicious technical choices: simple and robust protocols, open standards, and decentralized architecture. The system adapted to evolving uses without ever breaking its fundamental compatibility. The emergence of instant messaging and social networks has not succeeded in completely dethroning this sixty-year-old technology, which continues to route more than 350 billion messages across the planet each day in 2024.