How did the “@” symbol become part of email addresses?

Ray Tomlinson picked the @ symbol in 1971 because he needed a character that would never appear in someone's username. The @ was sitting there on the keyboard, rarely used for anything except accounting notation ("10 items @ $5 each"), and it had a natural meaning: "at."

Before Tomlinson's choice, there was no standard way to address a message to someone on a different computer. Early email systems only worked within a single machine. You could send a message to "kraken" if kraken had an account on your computer, but how do you tell the system that kraken is on a different machine entirely?

Tomlinson's solution: kraken@tidalmail. The username came first, the @ separated it from the host name, and the host name told the network which computer to route the message to. Simple, unambiguous, and it scaled perfectly as networks grew.

What makes the @ brilliant is what it doesn't do. It doesn't introduce ambiguity (is "kraken-tidalmail" one username or two parts?). It doesn't conflict with other syntax (dots, hyphens, and underscores were already used in usernames). And it reads exactly like English: "user at host."

The @ symbol's visual history goes back centuries. It appeared in Italian and Spanish merchant records as early as the 1500s as shorthand for the amphora, a unit of weight or volume. By the 20th century, it survived mostly on typewriter keyboards for accounting use. When computer keyboards inherited the typewriter layout, the @ came along for the ride. Tomlinson just gave it a second life.

By the mid-1980s, as email spread beyond academic networks, the @ became universal. Every email system adopted it. Today, it's so tied to email that in 2010, the Museum of Modern Art (MoMA) in New York "acquired" it for their permanent design collection, recognizing it as one of the most elegant symbols in digital communication.

So one detail that often surprises people: Tomlinson didn't Patent the @. He didn't trademark it. He just used it, and the rest of the internet followed. That kind of organic adoption is rare in tech, and it's part of why email addresses look the same everywhere, from Gmail to ProtonMail to corporate mail servers running Microsoft 365.

Want to see how Tomlinson's work fits into the bigger picture of email's early days? Check out ARPANET's role in email or read about who actually invented email (spoiler: it's complicated).