We can help you to get the lowest possible postal rates by sorting the mail according to the United States Postal Service (USPS) requirements and regulations. Because Roadrunner Mailing Service does the work of sorting the mail, it costs the Postal Service less money to process and deliver those pieces of mail, resulting in lower postage for you. We "presort" the mail by zip code, grouping pieces that go to the same destination into bundles and trays. These trays must be prepared according to the USPS requirements with proper labeling and paperwork. Roadrunner Mailing Service will handle all of the work for you while providing postage savings.