The Greek historian Xenophon credited Cyrus the Great (who ruled in 580 to 530 BC) with the invention of the postal system, but the first document that mentions post was found in Egypt, dating back to about 2000 BC.
The Egyptian document is a will sent by a father to his son telling the latter of the bright future that awaited a scribe in government posts, according to Tour Egypt. Mail during the time of the pharaohs was probably distributed by postmen who traveled on foot. They may also have followed the paths of caravans and armies to send messages to other countries.
However, Xenophon credited Persia's Cyrus the Great with the invention of the postal system, according to Farsinet.com. Cyrus built posting stations across his empire to ensure the efficient exchange of information between him and his governors, known as satraps. Although the Egyptians invented the postal system, Cyrus may have improved upon the concept during his rule.