Per state law, it must be a minimum of 11" wide, 14" high, 1" lettering and PROMINENTLY displayed. The mall does not follow this law. According to city code, however, one could post it on a postage stamp sized poster in the corner under the eaves and be in compliance of a notice. There is no size or placement requirement.As I understand Missouri law in this particular instance, no crime is committed until a carrier is told to leave the premises and refuses. I would ignore the sign and go on about my business. That's just me, of course.