The Free On-line Dictionary of Computing (30 December 2018):
play by electronic mail PBEMA 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)