Wiktionary
postal box
n. A post-office box.
Usage examples of "postal box".
Tungston: I phoned the main post office, confirmed the existence of a Post Office East, got directions as to how to get there, looked for a postal box key in Mr.
Percy, to their surprise, used a postal box in Atlantic Beach, one rented to an outfit called Laurel Ridge.
And then a postal box number in Everglades City, not far from Marco Island.
He learned that Seismic Services was an account with a postal box for an address.
A man passed on his way to his postal box, fumbling in his pocket for his key, muttering something to himself.
If anything happens while you are gone, now or later, I'll make a chalk mark on the side of the postal box on the fourteen hundred block of Na Perslyne.