Source : Free On-Line Dictionary of Computing

play by electronic mail
     
         A kind of game where the players use {electronic mail}
        to communicate.  This may be done via a human {moderator} or
        an automatic {mailing list} {exploder} on some central machine
        or it may be fully distributed with each player just
        addressing his mail to all other players.
     
        This is a natural extension of "play by mail" games conducted
        via {snail mail}.
     
        {(http://fermi.clas.virginia.edu/~gl8f/pbm.html)}.  {Usenet}
        newsgroup: {news:rec.games.pbm}.
     
        (1994-10-27)