@

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, it's used in some command-line utilities that connect to a remote host, such as Secure Shell (ssh jdoe@example.net tries to establish a Secure Shell connection to the computer with the hostnameexample.net using the username jdoe).