Number Four: Send. Reply. Delete.In 1971, Ray Tomlinson, an MIT alum working at Bolt Beranek and Newman, a Cambridge consulting firm founded by other MIT alums, sent the first e-mail between two computers on the Arpanet (the Internets predecessor). He picked the @ to separate the users name from the computer host where he could be reached. When Tomlinson showed his e-mail system to another BBN employee, he reportedly said: Dont tell anyone! This isnt what were supposed to be working on.