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@Mail Electronic Mail – 1971 AD

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Ray Tomlinson (1941–2016)

Many early time-sharing systems allowed users to leave messages for one another. For example, early PDP-10 systems had a program called SNDMSG that let a user compose a message and then append it to another user’s mailbox. When the second user logged in, he or she could see the message that the first user had left by running another program, READMAIL. The messages composed and displayed with these programs, however, were confined to a single computer.

In 1971, Ray Tomlinson, an engineer at BBN, developed a program called CPYNET for sending files between computers. Shortly thereafter, Tomlinson realized that he could combine aspects of SNDMSG and CPYNET. A user could author a message with CPYNET and use a modified version of the CPYNET protocol to deliver the message to another computer, where it would be appended to the specified user’s mailbox. Shortly thereafter, Tomlinson sent a message between two computers in BBN’s Cambridge, Massachusetts, laboratory. Tomlinson didn’t keep that first message, but he told numerous journalists that it was probably the keyboard pattern “QWERTYUIOP.”

Beyond sending the first network mail message, Tomlinson is also credited with choosing the @ symbol to separate the name of the mailbox from the name of the destination host. Instead of its original meaning to denote prices—e.g., 2 eggs @ 35¢ = 70¢—the sign soon represented the middle part of a network mail address.

The original ARPANET had been designed to support remote computer access through virtual terminals and file transport; mail was not part of the initial design. Nevertheless, mail soon became ARPANET’s “killer app”—the reason that many research laboratories spent time and money to get on the network. No doubt this was helped along by ARPA’s tendency to use email for official business: researchers who found it easy to exchange email with ARPA program managers also found it easier to get funding.

Despite the adoption of the @ sign for mail, the From:, Date:, and Subject: mail headers would not be standardized until ARPANET standard RFC 561, Standardizing Network Mail Headers, was adopted in 1973. The To:, Cc:, and Bcc: headers would have to wait for RFC 680, Message Transmission Protocol, adopted in 1975.

SEE ALSO Time-Sharing (1961), ARPANET/Internet (1969)

BBN engineer Ray Tomlinson chose the @ symbol to separate the name of a users mailbox from the name of the destination host.

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