is Mail Art?
Correspondence art (Mail art)
applies to art sent through the post rather than displayed or
sold through conventional commercial channels, encompassing a
variety of media including postcards, books, images made on photocopying
machines or with rubber stamps, postage stamps designed by artists,
concrete poetry and other art forms generally considered marginal.
Held Jr. The Dictionary of Art, edited by Jane Turner, Macmillan
Publishers Limited 1996