The main purpose of the Postal Processing Protection Act is to establish specific requirements that the United States Postal Service (USPS) must follow when closing facilities that support post offices. This includes not just post offices themselves, but also various other facilities involved in the acceptance, processing, shipping, and delivery of mail. The key provisions of this legislation involve amendments to existing laws regarding the closure of postal facilities. It broadens the definition of what constitutes a facility that supports a post office.