FedEx Corp. generated more than $1.6 billion in revenue from the U.S. Postal Service (USPS) in the post office's 2012 fiscal year ending last September, making FedEx by far the postal service's largest supplier, according to internal USPS data obtained by a Washington, D.C.-based law firm.

This marks the 10th consecutive year that Memphis, Tenn.-based FedEx, which competes with USPS on various delivery services, was also the quasi-governmental agency's largest supplier, according to Husch Blackwell LLP, which obtained the information through a Freedom of Information Act request.
USPS's air contract brought FedEx $1.6 billion in fiscal 2012, internal documents show – DC Velocity