the US government

Ray Tomlinson invented the use of the @ symbol in use with e-mail E-mail predates the inception of the internet, and was in fact a crucial tool in creating the Internet. MIT first demonstrated the Compatible Time-Sharing System (CTSS) in 1961. [1] It allowed multiple users to log into the IBM 7094 [2] from remote dial-up terminals, and to store files online on disk. This new ability encouraged users to share information in new ways. E-mail started in 1965 as a way for multiple users of a time-sharing mainframe computer to communicate. Although the exact history is murky, among the first systems to have such a facility were SDC's Q32 and MIT's CTSS. E-mail was quickly extended to become network e-mail, allowing users to pass messages between different computers. The messages could be transferred between users on different computers by at least 1966 (it is possible the SAGE system had something similar some time before). The ARPANET computer network made a large contribution to the evolution of e-mail. There is one report which indicates experimental inter-system e-mail transfers on it shortly after its creation, in 1969. Ray Tomlinson initiated the use of the @ sign to separate the names of the user and their machine in 1971. The ARPANET significantly increased the popularity of e-mail, and it became the killer app of the ARPANET. ripped from http://en.wikipedia.org/wiki/E-mail#Origins_of_e-mail