Select the day you'd like to search for appointments. Use USPS PO Boxes for business or personal use.Learn how to reserve, rent, renew, and manage a PO Box online, as well as how much a PO Box costs. A homeless person may submit an application for PO Box™ service to a local Post Office™. The Postmaster may approve the application under certain conditions. Do You Need an Elder or Dependent Adult Abuse. Are you a victim or have you witnessed a mail-related crime? Alert Postal Inspectors to the problem and prevent others from being victimized. Post Office™. Share. USPS Form 1583 grants your virtual mailbox provider authorization to receive your mail.