Pricing: Starts at $4.05 for a flat-rate envelope. Service: Average 2-3 days for delivery, Monday-Saturday Packaging Requirements: Please mark "Priority Mail" in the postage area or use a USPS-provided Priority Mail sticker or packaging Package must weigh 70 pounds or less and measure 108 inches or less in combined length and girth (measure around all 4 sides of package). Other features: Can be combined with Delivery Confirmation™, Certified Mail™, Registered Mail® or Insurance.