How To Use Box number In A Sentence

I always had some idea you were a travelling salesman, always writing to you at a box number. YESTERDAY'S SHADOW
The letter, which came from an address in London, tells recipients to quote box numbers when replying.
The most secret sites were always referred to by their post-box number. CHAMELEON
So she wrote to the box number and suggested a date for a preliminary viewing to avoid disappointment or misunderstandings.
But now, waking up from The Obama Show is like being on "Let's Make a Deal" and trading in your winning prize hidden under box number 1 for the "zonk" behind curtain number 2. American Thinker

So she wrote to the box number and suggested a date for a preliminary viewing to avoid disappointment or misunderstandings.
These advertisements generally use a Box number at the publication as the contact address and may be placed by the client.
These advertisements generally use a Box number at the publication as the contact address and may be placed by the client.
Your mother wasn't so proud,' he said, and she remembered safe-deposit box number 718 sliding back into its wall. THE COMPANY OF STRANGERS
Each one was labelled with a box number and contained a large brown envelope.
Take, for example, the closed city of Ozersk, a community of 85,000 people, whose existence was so hushed under the Soviets that it was not allowed a proper name, and was referred to only by its post office box numbers — first No. 40, then No. 65 — in Chelyabinsk, an open city forty-four miles away. How to Get a Nuclear Bomb