For years, the USPS had more than 30 bulk mail service centers (BMC), but more recently the bulk mail center network has been redesigned into a new system called network distribution centers (NDC). This consolidation of postal facilities is an effort to decrease the USPS overhead and increase its efficiency. An NDC accepts and processes mail from other postal facilities across the nation that eventually gets delivered within its service territory. Learn how bulk mail works with network distribution centers to increase efficiency and reduce your overall postage costs.