A method and apparatus for processing mail is provided. The mail is serially fed from a stack of mail into a system transport (40). The system transport conveys the mail to an imaging station (45), which scans the mail to obtain image data corresponding to at least a portion of each piece. From the imaging station, the mail is conveyed to a buffer (50), which selectively maintains the mail while the address printed on the mail is determined. After the address for a piece of mail is determined, the piece is conveyed out of the buffer to a printer (80), which prints a POSTNET barcode onto the piece. The POSTNET barcode corresponds to the address that was determined for the piece. Optionally, the apparatus may include a labeller (70) for applying a blank label onto the mail, and the POSTNET barcode can then be printed onto the label after it is applied to the mail. After the POSTNET barcode is printed on a piece, it is conveyed past a verifier (85), which scans the printed POSTNET barcode to ensure that the barcode was printed properly. The mail is then sorted and stacked in a plurality of output bins (96, 97, 98, 99).