While the functioning of the postal system in Iran before 1500 and after 1800 has been studied, this article analyzes, based entirely on primary sources, the operation and characteristics of the Iranian postal system between 1500 and 1800 for the very first time. Such a study enables scholars to better understand the functioning of communication between both government officials and private individuals in Safavid, Afshari, and Zand Iran. During this time, there were two types of messengers: express-mounted couriers (chapar) for official business and foot messengers (shaters) for both official and private mail. The designation of qased was rarely used to denote mail foot messengers.