“sndmsg, for “send message.” Invoke it, and the thing would ask you for a To: field, a From: field, and a Copy: field, plus a few other options. Then you would type your message and hit Control-Z, and off it would go. At the other end, the recipient could see what you’d sent by invoking a companion utility that Tomlinson called readmail. In writing these utilities, moreover, Tomlinson had come up with an elegant way to define E-mail addresses: take the “user name” that the person typed when logging in to his or her host computer, and simply link it to that computer’s “host name” on the network with an “at” sign: username @ hostname.”