usps priority mailer

usps priority mailer USPS Priority Mailer refers to the various envelope and box options provided under the Priority Mail service, including flat-rate and regional rate mailers. These are ideal for shipping documents, apparel, and small goods quickly across the U.S. with delivery typically in 1–3 business days. Each mailer includes tracking and built-in insurance. The flat-rate feature simplifies cost planning, making it attractive for ecommerce and personal shippers alike. USPS Priority Mailers are available at post offices or can be ordered online for free.