1971 The first e-mail is sent between two machines and the @ sign comes into its own.
Although electronic mail had been available for many years, until this point users had only been able to send a message to other terminals connected to the same computer. To remedy this Ray Tomlinson at BBN modified an experimental file transfer protocol to carry electronic mail and tried sending a message between one machine and another. During the process he has to decide how to separate the two elements of the e-mail address, the name of the machine and the name of the user on that machine – he chooses the @ sign.

Although this first e-mail only crossed from one computer to another in a Cambridge (USA) office, there was nothing fundamentally different between doing this and sending a message across to any other computer connected to the ARPANET.

Later in the year the formal specification for the ARPANET file transfer protocol was finalised and the ability to carry electronic mail was included. Soon e-mail was widely available across ARPANET.

Ray Tomlinson's account of the first Internet E-mail.