[Postal Service-Air Force Postage Billing Dispute]

The Postal Service and the Air Force requested a decision as to whether the Air Force must pay certain disputed postage bills that were calculated on the basis of a statistical sampling method. The Air Force complained that the Postal Service incorrectly calculated certain rates and misapplied others. GAO held that, although the postal rates often were not precise, they were not demonstrably unreasonable. Further, the Air Force failed to establish a more realistic estimate for the postal bills. GAO also held that the Air Force was liable for the cost of certain bulk mailings because it used an incorrect and less expensive method to send bulk mail. Accordingly, the Air Force was liable for payment of the disputed postage bills.