CIO — When Ray Tomlinson merged two computer protocols, he had no idea he was creating what would become a staple of modern communication. "It seemed like a neat idea," says Tomlinson of his now 30-year-old creation. "There was no directive to go forth and invent e-mail."

Tomlinson, then a programmer at Bolt, Beranek & Newman, an engineering company in Cambridge, Mass., was part of a team working on the ARPAnet, the predecessor of the Internet. He had already written a mail program awkwardly named Sndmsg/Readmail that let users write and send messages from one so-called mailbox to another, but a mailbox was just a message file. The recipient could add to but not alter the message’s content. Tomlinson had also written an experimental FTP called CYPNET that let users send and receive files over a network connection, so in late 1971, he decided to link the two programs.

At the time, no one knew the extent to which e-mail would redefine business and personal communication. Even when Tomlinson told his coworkers what he had done, they were nonplussed. "No one had a vision of e-mail becoming a motivating factor for using computers in the future," he says.

When Tomlinson, now a principal scientist at BBN Technologies (the engineering company formerly known as Bolt, Beranek & Newman), a Verizon company, linked the two programs, he was able to send messages between two computers via a network. He chose the @ symbol to separate the user’s name from the host computer name. The rest is history.

Though he’s frequently asked how and why he created e-mail, Tomlinson says he has experienced very few negative repercussions outside of the occasional embarrassing question. "Sometimes people want to know why I didn’t prevent spam," he says.