Cicero on Letter Carriers

In my pre-bed time reading, I’m working through the letters of Marcus Tullius Cicero. Came across this interesting statement about letter carriers:

In these letters, indeed, I am urgently pressed by you to send answers, but what renders me rather dilatory in this respect the difficulty of finding a trustworthy carrier. How few of these gentry are able to convey a letter rather weightier than usual without lightening it by skimming its contents! (Letter XVIII).

This would suggest that some letter carriers were not just Roman fedex delivery boys, but were responsible for reading the letters on delivery. Interesting implications for the role of Phoebe in Romans and Tychicus in Colossae!