The first email was sent in 1971 and used the at sign to separate the user name from the machine.
Why it is true
Ray Tomlinson, an ARPANET engineer, sent the first email in 1971. He chose the at sign because it was not used in people's names or machine names, and it became one of the most recognisable symbols of the digital age.
Source: Internet Hall of Fame
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Related facts
The '@' symbol is officially called the 'commercial at'.
The first email message used the @ symbol to separate the user from the machine.
The first email ever sent was by Ray Tomlinson to himself in 1971, and it reportedly said 'QWERTYUIOP'.
90% of the world's emails are spam.