The Jargon File (version 4.4.7, 29 Dec 2003):
shitogram /shit'oh?gram/, n. A really nasty piece of email. Compare nastygram, flame.The Free On-line Dictionary of Computing (30 December 2018):
shitogram /shit'oh-gram/ A *really* nasty piece of e-mail. Compare nastygram, flame. [Jargon File] (1994-12-21)