For anyone who would like to read about this hazardous occupation of postman in the Trans-Mississippi, here is a link to an online text that might be of interest:
The Confederate Mail Carrier; or, From Missouri to Arkansas through Mississippi, Alabama, Georgia and Tennessee. An unwritten leaf of the "Civil War". Being an account of the battles, marches and hardships of the First and Second brigades, Mo., C. S. A. Together with the thrilling adventures and narrow escapes of Captain Grimes and his fair accomplice, who carried the mail by "underground route" from the brigade to Missouri.