I wanna know how the mail works, I wanna hang out with the mail clerks.
The letter first gets organized by the zip code’s first digit, to determine east-to-west which zone it is to visit. The second digit provides a north-south coordinate, the third gets the letter to the correct state. The fourth gets it sent to the county proper, the fifth gets it delivered to your local post office.
From there the local mail’s divided into routes, and the postal carrier brings the letter directly to your house. This may or may not be how the mail works, it is just a sketch, and it is not based on fact, just on my best guess.