Sometime in late 1971, a computer engineer named Ray Tomlinson sent the first e-mail message. "I sent a number of test messages to myself from one machine to the other," he recalls now. "The test messages were entirely forgettable... Most likely the first message was QWERTYIOP or something similar."

Ray Tomlinson, a Principal Scientist at BBN, sent the first network email in 1971. Tomlinson was part of a small group of programmers who were developing a time-sharing system called “TENEX” that, by the time, was running on most machines on the ARPANET.

The early mail program consisted of two parts; a program called SNDMSG for sending messages and another program called READMAIL for receiving messages. SNDMSG allowed a user to compose, address, and send a message to other users’ mailboxes which shared the same computer. However, in the early 70s, a mailbox was simply a file with a particular name. The only way that it differed from a regular file was that other users could only add to the file. They could not read or overwrite what was already there. Like other mail programs at the time, SNDMSG/READMAIL was created for time sharing systems and capable only of handling messages among the various users of individual machines, but it could not transmit messages from one machine to another.

Tomlinson was also working on an experimental file transfer protocol called CPYNET. CPYNET could send and receive files to computers through a network connection, but did not allow users to add any information to the files as SNDMSG did. Therefore, the idea occured to him to incorporate the CPYNET code into the SNDMSG code so as to enable it to direct message through a network connection to remote mailboxes in addition to appending messages to local mailbox files.

In late 1971, Tomlinson sent the first message between two machines that were side-by-side in his Cambridge, MA lab. He sent messages back and forth from one machine to the other until he was satisfied that the program worked. The first e-mail message he sent out of the lab was to the rest of his group announcing the existence of network e-mail and explaining how to use it, including the use of the @ sign to separate the user’s name from the host computer name. Now there was nothing to prevent the sending of messages out to the wider network.

“It just seemed like a neat idea. There was no directive to “go forth and invent e-mail”. The ARPANET was a solution looking for a problem. A colleague suggested that I not tell my boss what I had done because e-mail wasn?t in our statement of work. That was really said in jest because we were, after all, investigating ways in which to use the ARPANET.”