Scrabble?! POSTRIDER

Definitions of POSTRIDER in various dictionaries:

Post riders or postriders describes a horse and rider postal delivery system that existed at various times and various places throughout history. The term is usually reserved for instances where a network of regularly scheduled service was provided under some degree of central management by the State or State licensed monopoly. These networks included predefined routes known as Post-roads complete with distance markers and waypoints. Unlike other forms of mounted courier, post riders collected and delivered mail over the course of their route, meeting with other riders at scheduled times and scheduled places to exchange forwarded items. In this way correspondence could pass reliably from rider to rider and cover a considerable distance in a reasonable time at reduced cost. While some integration with local postal services in larger centers occurred, by and large the post riders were a separate entity under separate management and tariff structure.