When you have a post-office box, the postman doesn't bring letters to you, but you go to the post-office and get your letters and parcels from your box. The box is locked, only you have the key, so the letters and parcels are safe. One day the headmaster of a school wrote to the post-office and asked for a post-office box for his school. He soon got an answer. It said, "We will give you a post-office box in one month." Three months later, the headmaster wrote to the post-office and said, "Why haven't we got a post-office box yet?" This was the answer from the post-office: "Dear sir, We gave you a post-office box two months and wrote to you then to tell you. Here is the key to your box. You will find our letter to you in it." Which of the following might not be true?
If you want to get a post-office box, you must let the post-office know. When you get a post-office box, you have to do the work of a postman. You go to the post-office to get the key to your box. After you get a post-office box, the post man will not send mails to your house.