Computer sorting of mail just does not work as well as humans.
Recently I sent a letter to a friend who happens to live near the border of several towns. His legal residence is in one town in Vermont, while his mail is delivered by the post office in the adjacent town.
When I addressed the letter, I used his legal address, because that's the one I had used when finding his house using google maps.
The letter was returned to me as "no such street, unable to forward."
My friend reports that the human postal carriers were able to figure out such addressing, but the computer sorting facility cannot.
This is really annoying. I sent the letter to the correct, legal address of my friend's house. The fact that the postal service elects to deliver mail from the post office of the neighboring town is supposed to be for postal service convenience, not to inconvenience postal service customers. The computer should be programmed to figure such addresses rather than sending letters back to senders.
Even more annoying, when I went to usps.com, to try to send in an e-mail complaining of this situation, I found a bunch of options for complaining about mail service -- and none of the options applied to this situation. They don't have a category for "other" complaints. They can't imagine that someone might come up with a complaint that doesn't fall into the categories they have pre-selected.
Again a human being would be able to take a miscellaneous complaint that doesn't fit into other categories.