us postal service priority mail tracking US Postal Service Priority Mail tracking provides real-time updates from drop-off to delivery, accessible via the USPS website or app using the tracking number. Updates include acceptance, transit checkpoints, expected delivery, and delivery confirmation. Priority Mail typically arrives within 1-3 business days and includes up to $100 in insurance. Tracking ensures visibility for senders and recipients, reducing uncertainty and enabling issue resolution if delays or address problems arise. It’s widely used for both personal and business shipping.