Was it possible for davey Crockett to send a letter via pony express?

No, it was not possible for Davy Crockett to send a letter via Pony Express, as the Pony Express was established in April 1860, several years after Crockett's death in 1836. During Crockett's time, other means of communication were used, such as traditional postal services or messenger riders. The Pony Express was a notable service for fast mail delivery across the American West but did not exist during Crockett's lifetime.