Grand Banquet

"I also have to develop the postal system" 

Aeryon of course had this idea from what he reads about Genghis Khan

that Genghis Khan created a postal system to help him communicate better and giving and receiving news a lot faster.

"Was it the Yam?" he thought to himself

Aeryon search his memories and he nodded to himself

The Yam or Ortoo, the communication/postal relay system, grew out of the Mongol army's need for fast communication. 

As the empire of the Khan grew, it eventually incorporated some twelve million square miles, the largest contiguous land empire in world history. 

Genghis Khan set up a system of postal/relay stations every twenty to thirty miles. 

A large central building, corrals and outbuildings comprised the station. 

A relay rider would find lodging, hot food and rested, well-fed horses. 

The rider could hand his message to the next rider, or he could grab a fresh horse, food and go.