usps letter size first class

usps letter size first class is a specific category of USPS First-Class Mail that includes letters, postcards, and other small items. First-Class letters must meet specific size requirements to qualify for this service. For letters, the dimensions should be at least 3-1/2 inches high by 5 inches long and not exceed 6-1/8 inches high by 11-1/2 inches long. These items are typically used for personal correspondence, invitations, or important documents. USPS First-Class Mail offers fast, affordable delivery, with typical delivery times ranging from 1 to 3 business days within the U.S.