

Who invented e-mail? That's a bit like asking, "Who invented the internet?" Even those with intimate knowledge of its creation can't agree on the moment it actually came to life. But amid all the bluster over the origins of e-mail, one man holds a claim that resonates well beyond the rest.

Ray Tomlinson is the reason your e-mail address includes an '@' symbol.

For this reason – and many others – you wouldn't be remiss in calling Tomlinson the inventor of e-mail. And many do. Earlier this year, in recognition of the seminal electronic mail system he created in 1971, Tomlinson was inducted into the inaugural class of the Internet Society’s (ISOC) Internet Hall of Fame, alongside such pioneers as Vint Cerf, Sir Tim Berners-Lee, and Van Jacobson.

After completing an electrical engineering master's degree at MIT in the mid-'60s and spending a few more years at the university working on a doctorate, Tomlinson wound up at Bolt Beranek and Newman, aka BBN, a Boston company that played a key role in the creation of the internet. In the late-'60s and '70s, BBN built much of the hardware and software that underpinned the internet's precursor: the ARPAnet, a government-funded network that connected various research organizations across the country.

BBN built the ARPAnet's IMPs – or Interface Message Processors – that plugged each research outfit into the sprawling network. Typically, these IMPs – akin to modern network routers – were plugged into computer mainframes known as DEC PDP-10s, and in 1971, Tomlinson and BBN colleague named Jerry Burchfiel were charged with building what amounted to a new operating system for these machines.

This meant they were connected to ARPAnet themselves. But it also meant they were plugged into the relatively small community of researchers working to improve the thing. Thanks to a man named Steve Crocker – another Internet Hall of Fame inductee – the community regularly exchanged ideas by way of documents called Request for Comments, or RFC. One day, Tomlinson came across an RFC that proposed a protocol for sending and receiving mail on the network.

Computer scientists had exchanged messages on machines for years. Some trace e-mail all the way back to the mid-1960s and MIT’s Compatible Time-Sharing System (CTSS), essentially a massive computer that many people could remotely log in to. With CTSS, users could exchange information by storing files on the machine's discs, and in 1961, a man named Tom Van Vleck developed a "mail" command that let users send electronic messages to each other. But these messages didn't actually travel across a network. They remained on a single machine.

After reading the RFC, Tomlinson discarded its particulars. But he went to work on messaging system of his own, using an old time-sharing messaging program as a starting point. "The RFC seemed very complicated," he says. "I thought I could do something that was simpler – but much better." This became the ARPAnet's "SNDMSG" command – short for "send message" – and it used addresses that depended on the '@' symbol. Much like today, the symbol sat between the name of the user you were trying to reach and the place where you could reach them – in this case, their host computer.

"I looked at the keyboard, and I thought: 'What can I choose here that won't be confused with a username?'" Tomlinson remembers. "If every person had an '@' sign in their name, it wouldn't work too well. But they didn't. They did use commas and slashes and brackets. Of the remaining three or four characters, the '@' sign made the most sense. It denoted where the user was ... at. Excuse my English."

Tomlinson calls the '@' symbol "the only preposition on the keyboard."

The first message traveled between the two ARPAnet machines operated by BBN. But Tomlinson doesn't remember what he sent. "They were all test messages, and whatever came to hand as I put my fingers on the keyboard is what I would send," he says. "The first one could have said almost anything."

By 1972, Tomlinson and BBN had delivered their "SNDMSG" program to the other dozen or so sites on the ARPAnet. And eventually, the '@' went everywhere. Tomlinson – who still works at the modern incarnation of BBN – didn't call his system e-mail or electronic mail. But he says the term was in use among the ARPAnet cognoscenti by the mid-'70s.

Some point to MIT's Van Vleck – who built that time-sharing mail system 10 years before Tomlinson put together his ARPAnet program – as the inventor of e-mail. Others point to Tomlinson. And still others point to a 14-year-old from New Jersey, who says he coined the term e-mail seven years after Tomlinson's big moment. But these are largely arguments of semantics. You know that words are the issue when Noam Chomsky gets involved.

"There seems to be little disagreement over who wrote what, and approximately when," Van Vleck tells Wired. "The argument is over what to call things."

But there's no arguing with Tomlinson's '@' sign.

Image: Flickr/whlwcl