Berean Study Bible
Mordecai wrote in the name of King Xerxes and sealed it with the royal signet ring. He sent the documents by mounted couriers riding on swift horses bred from the royal mares.

King James Bible
And he wrote in the king Ahasuerus' name, and sealed it with the king's ring, and sent letters by posts on horseback, and riders on mules, camels, and young dromedaries:

American Standard Version
And he wrote the name of king Ahasuerus, and sealed it with the king's ring, and sent letters by post on horseback, riding on swift steeds that were used in the king's service, bred of the stud:

Darby Bible Translation
And he wrote in the name of king Ahasuerus, and sealed [it] with the king's ring, and sent letters by couriers on horseback riding on coursers, horses of blood reared in the breeding studs:

Douay-Rheims Bible
And these letters which were sent in the king's name, were sealed with his ring, and sent by posts: who were to run through all the provinces, to prevent the former letters with new messages.

English Revised Version
And he wrote in the name of king Ahasuerus, and sealed it with the king's ring, and sent letters by posts on horseback, riding on swift steeds that were used in the king's service, bred of the stud:

Young's Literal Translation
And he writeth in the name of the king Ahasuerus, and sealeth with the signet of the king, and sendeth letters by the hand of the runners with horses, riders of the dromedary, the mules, the young mares,