This invention relates to a machine for franking mail items, comprising
means for printing postal indicia on a mail item, means for detecting the
position of this mail item along a path of travel of this item and
control means linked to said detection means and to said printing means
for proceeding with printing postal indicia on said mail item at a
predetermined place, and means for acquisition and processing of an image
of such printed postal indicia so as to determine the conformity thereof
with respect to at least one predetermined reference image. These image
acquisition and processing means comprise in particular means for
determining a lack of registration of said printed postal indicia.