Mail is a type of armor, consisting of myriad rings of metal woven into a form; it is sometimes redundantly (and erroneously) termed “chain mail”. Mail gauntlets, coifs, and shirts have been used in period heraldry – usually worn on a human, but sometimes charges in their own right, as in the mail shirt (illustrated) in the canting arms (from dial. Italian maja or maglia d’arme) of de Mayete, mid-15th C. [Triv 235].
There have also been cases of ordinaries being drawn as mail: e.g., “a bend of mail”, showing the field through the rings. This had been justified by the period examples of ordinaries of chain; the practice has been discontinued, and is no longer registered in Society armory. (This should not be confused with ordinaries maily, which are solid charges bearing a field treatment.)
James of Penmore bears: Vair ancient, a sinister arm embowed, armored and gauntleted of chain mail sable, grasping a closed book gules.
Rhiannon Mor MacFhearghius bears: Gules, a bend sinister of chain mail between two Arabic lamps Or.