The selection of the @ symbol as a separator in email addresses in 1971 by Raymond Tomlinson established a convention that remains fundamental to global digital communication. While adapting existing software to allow messages to travel between different machines on the ARPANET, he implemented a format that finally enabled users to distinguish between individual accounts and their respective host computers.
Academic Foundation
Born in Amsterdam, New York, in 1941, Tomlinson followed an education in electrical engineering that spanned two prominent institutions. He earned a bachelor's degree from Rensselaer Polytechnic Institute in 1963, having participated in a co-op program with IBM. He subsequently enrolled at the Massachusetts Institute of Technology, where he focused on speech synthesis. By 1965, he had completed his master's degree, having integrated digital systems into his thesis project after becoming engaged by the early computer game Spacewar!.
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In 1967, Tomlinson joined BBN Technologies, where he contributed to the development of the TENEX operating system and the ARPANET Network Control Program. His technical contributions extended to the implementation of Telnet and various experimental programs, such as Creeper and Reaper. During this tenure, he also created CPYNET, a file transfer utility that allowed data transmission between disparate computers. This groundwork provided the necessary architecture for his later development of network-based electronic messaging.
The Creation of Networked Email
Tasked with adapting an existing local messaging program, SNDMSG, to operate on TENEX in 1971, Tomlinson innovated by incorporating code from his CPYNET project. This modification enabled communication across the ARPANET. He chose the @ symbol to designate the recipient's location because it was not used in usernames and was not part of the TENEX syntax. Although he initially viewed the invention as a minor, informal project, the system was quickly adopted by the research community. Tomlinson is also recognized for developing the TCP three-way handshake, a protocol that provides the backbone for modern Internet communication.
Professional Recognition and Legacy
Over the course of his career, Tomlinson received numerous accolades, including the 2004 IEEE Internet Award, the 2009 Princess of Asturias Award, and induction into the Internet Hall of Fame in 2012. Despite his technological impact, he maintained a minimal personal relationship with consumer devices. Tomlinson passed away in Lincoln, Massachusetts, on March 5, 2016. In recognition of his influence, his birthday, April 23, is commemorated as Email Day.
Fast facts
- Born: 1941, Amsterdam, New York
- Died: 2016, Lincoln, Massachusetts
- Education: Rensselaer Polytechnic Institute, Massachusetts Institute of Technology
- Primary Employer: BBN Technologies
- Notable Innovations: Email, @ symbol, TCP three-way handshake
- Internet Hall of Fame Inducted: 2012
- Award: IEEE Internet Award (2004)
Questions readers ask
What was the content of the first email?
Tomlinson described the first test messages as insignificant and forgettable, noting they were likely random strings of characters such as QWERTYUIOP.
Why did he use the @ symbol?
He selected the symbol to clearly separate a user's name from their host machine's name, choosing it because it was not used in programming or usernames.
Achievements
- Internet Hall of Fame — 2012
- Notable work: email
- Notable work: TENEX
- Notable work: @
- Affiliated with BBN Technologies
- Educated at Rensselaer Polytechnic Institute and Massachusetts Institute of Technology
- Worked as programmer, inventor and patent inventor
