How To Mail USPS First Class Envelopes & Packages with Stamps
A. If a mailpiece does not exceed 11-1/2 inches x 6-1/8 inches x 1/4 inch thick and 3.5 ounces, but is rigid, it is classified and priced as a nonmachinable letter (i.e., applicable First-Class Mail postage and $0.17 nonmachinable surcharge apply). Q.