Happy birthday: Email @ 30

The common or garden email celebrates its thirtieth birthday today. In the autumn of 1971, a US engineer called Ray Tomlinson wrote a 200-line program that later became known as email.

The program allowed a user to send a message to any computer hooked up to Arpanet, the forefather of today's internet, which was developed by the US Department of Defense.

Tomlinson begun to develop an experimental file transfer protocol back in late 1960s for transferring files across Arpanet, which at the time consisted of a total of 15 computers. The CYPNET program he created allowed files to be sent to and from the interconnected machines.

Tomlinson then wrote a messaging program to distinguish between messages addressed to the mailbox of a local machine, or those connected via Arpanet. The symbol he chose to act as a differentiator between messages was the @ character.

By combining the two programs, email was born.

Tomlinson later said in an interview: "The @ symbol seemed to make sense. I used the symbol to indicate the user was at some other host rather than being local."

The first message was likely to have been sent between two machines resting side-by-side and containing the message QWERTYUIOP (the top line of letters on the keyboard) in capital letters - although Tomlinson says he can't remember exactly what the message was.

He also modestly claims that both sorts of program already existed, and that what he did was "no major tour de force".

The early adopters of email were Arpanet engineers who found the new way of communicating was quick and perhaps more suitable to their personalities than a phone call or face-to-face conversation...