International Surface Air Lift® (ISAL®) service, including ISAL M-bags, is a commercial service designed for volume mailings of all First-Class Mail International postcards, letters, and large envelopes (flats), and for volume mailings of First-Class Package International Service packages (small packets). ISAL shipments are typically flown to the foreign destinations (exceptions apply to Canada and Mexico) and are then entered into that country’s surface nonpriority mail system for delivery. Separate prices are provided for international service center (ISC) drop shipments, presorted mail, and nonpresort mail. Volume incentives are available through customized agreements.