A. We require a 4.5 inch wide by 2.5 inch tall blank white box in the bottom right hand corner of the piece. This blank box may only contain the return address in its upper left-hand corner, as well as the mailing indecia, which we will add. Contact us for samples as to where the USPS requires placement for various pieces, as the new regulations and Intelligent Mail Barcode have specific requirements that are updated every six months.