At sign significant person Raymond Tomlinson
Email addresses
A common contemporary use of @ is in email addresses (using the SMTP system), as in jdoe@example.com (the user jdoe located at the domain example.com). Ray Tomlinson of BBN Technologies is credited for having introduced this usage in 1971. This idea of the symbol representing located at in the form user@host is also seen in other tools and protocols; for example, the Unix shell command ssh jdoe@example.net tries to establish an ssh connection to the computer with the hostname example.net using the username jdoe.
On web pages, organizations often obscure the email addresses of their members or employees by omitting the @. This practice, known as address munging, makes the email addresses less vulnerable to spam programs that scan the internet for them.