Jackass Mail (1942)

Tiny Tucker delivers mail and, attracted to her, Just Baggot becomes her new carrier. After he kills a man in a gunfight, the man's son joins him in the deliveries and they become good friends. But Baggot has two problems - alcohol and the urging of his friend Signor to rob the mail shipments. After the boy learns Baggot killed his father and leaves him, Baggot decides to join Signor in a train robbery. When other outlaws beat them to it, they have a chance to become heroes.