Can I Ship A Backpack Through First Class?
Can I Ship A Backpack Through First Class? Maximum weight for First-Class Mail letters is 3.5 oz; for large First-Class Mail envelopes and parcels, the maximum weight is 13 oz. All postcards and envelopes (or flats) must be rectangular, otherwise an additional charge may apply. What qualifies for USPS First Class package? First-Class Mail® is