Of course, Herodotus never had to consider postal regulations.
Another unpleasant run-in with the mail man had me at the computer searching for solace in the USPS motto. It turns out that there is no official motto:
What is the postal service motto?:
Actually, the U.S. Postal Service does not have an official motto. The phrase which most people associate with the postal office is that which is engraved on the outside of the James A. Farley Post Office building at 8th Avenue & 33rd Street in New York, New York: Neither snow nor rain nor heat nor gloom of night stays these couriers from the swift completion of their appointed rounds.

This phrase was a translation by Prof. George H. Palmer, Harvard University, from an ancient Greek work of Herodotus describing the Persian system of mounted postal carriers c. 500 B.C. The inscription was added to the building by William Mitchell Kendall of the architectural firm of McKim, Mead & White, the building's architects.
and thereby no official obligation. Beyond postal regulations.

We live in a cul de sac. There are many of us. Sometimes the mailbox is inadvertently blocked. The mailman takes it personally. Yesterday the mailbox was not blocked. But something else was awry - not the garbage cans, either - and he started yelling out of his truck about postal regulations forbidding him from pulling into a parking spot that he cannot back out of (?), slamming the box shut and hitting one of our garbage cans. If money weren’t a consideration, I would rent a PO box and avoid the box on the street altogether. Then we wouldn’t have to worry about where the mailbox should be - where the snow plow piles drifts in front of it or on the other side of the driveway, where people park in front of it. Let’s not talk about the school bus that hit it last month.