🚀 go-pugleaf

I am interested in finding early uses, hopefully the first use,
of "flame", and "flame on/flame off" in the electronic mail sense.
This is being done as a courtesy for the OED; the submitter of
the earliest cite may be able to point to his contribution in
some upcoming edition of the dictionary.  Only references before
1980 are interesting.  I suggest replying only to me and I will
eventually post the answer; my address is
  bellcore!lesk
  lesk@mouton.arpa
on uucp and Internet respectively.  Guesses as to the origin of the
use are also valuable if old.

Thank you.
Michael Lesk