Tomlinson was one of a group of scientists who were working on developing better computers. Th e
scientists at his site were able to send a message to a “mailbox” on the computer on their site. Other
scientists could view the messages in the mailbox. But there were other computers at other sites
where scientists were working on the same project. Tomlinson’s idea was to figure out a way to deliver
messages to mailboxes on those remote computers. He used the # sign to identify messages that were
headed out of the local machine to the more distant ones. That was the start of the emailing systems
that we still use today.