If you mail First-Class Mail International (FCMI) Large Envelopes (Flats), take notice: the USPS filed a notice to change the weight limitations.
According to the December 7 Industry Alert, if implemented, the maximum weight for FCMI would go from the current 64-ounce limit to 15.994 ounces. The request is currently being reviewed. The current 64-ounce limit is still in effect for now. We will keep you updated on this as more information becomes available.