Ray Tomlinson was just another computer programmer at Bolt, Beranek and Newman. One of his responsibilities was to help in the development of TENEX operating system and the Network Control Program of ARPANET.
The ARPANET was the network at Advanced Research Projects Agency (ARPA), a defence organization established as a result of the United States losing the “Space Race” when the Soviet Union launched Sputnik 1.
One fine day, he was asked to change a preexisting program called SNDMSG so that it could run on TENEX. The main function of SNDMSG was to send messages to users of a time-sharing computer. A precursor of the emailing system wherein users of the same computer could message each other was already in place.
Unknown to his employer, Tomlinson added code from a file transfer program he had created earlier to the SNDMSG program just to see if it would work. He was, after all, simply tinkering around. The modified program was able to send messages over the network from one computer (host) to another. The greatest communications method known to man was, thus, born.
Obviously, this was not a directive of his work and Tomlinson knew that. However, he was excited about it and told one of his colleagues, “Don’t tell anyone! This isn’t what we’re supposed to be working on“.
By the way, though the two computers between which the first email message was sent were placed side-by-side, they were connected to each other ONLY over ARPANET.
Ray Tomlinson is also credited to have been the first to use the “at” symbol (@) in an email address to separate the username from the computer (host) name.
Ed Krol's book, "The Whole Internet User's Guide & Catalog", was probably the first popular book about the new medium. It was published in 1992 and selected by the New York Public Library as one of the most significant books of the 20th century. [more...]