Where I live in Australia, we have three mail boxes out front. It’s at the bottom of a steep driveway, so someone needs to walk the letters up to the house. One mailbox is disused, and lies neglected on it’s side. One is usually empty - that’s mine, because I check it regularly - and the one is full of letters.
Full of actual letters: bills, a Xmas card, notices of many different kinds. Maybe there’s some junk mail there too, but not the kind of junk I would risk just throwing in the bin. However, my tenants downstairs never check their mailbox.