Look a little closer
The @ in an email address was not drawn specifically for the Internet. It was an old commercial and typewriter character that engineer Ray Tomlinson selected for a new role in 1971.
People could already leave short messages for others using the same computer. Tomlinson combined existing programs so a message could travel between different machines on ARPANET, and he needed notation separating a recipient's name from that person's computer.
The sign was read as 'at,' making the relationship intuitive: user@host meant a user at a host. It was already on keyboards but rarely appeared in login names or the relevant operating-system commands, reducing the chance of ambiguity.
That small choice divided an address into two parts. The local part on the left identifies a mailbox within a mail system, while the domain on the right indicates the system responsible for it. Modern email standards retain this basic structure.
It is too simple to say Tomlinson invented all electronic messaging. Same-computer mail and other precursors already existed. His pivotal contribution was sending mail to a user on another networked host and establishing the name@host convention.
The success of @ did not depend on inventing a spectacular new symbol. It was a strong interface choice: familiar, available, meaningful and able to express the relationship between a person and a computer in a single character.
