The post office spokesman said, "Technically, we own the inside of the there are some exceptions to what counts as a mailbox: "Door slots. My problem is if I drop them into my post office's metered mail slot (zip ) . Can you put that stupid scan sheet in the shipping label itself. I made the slot the the maximum width that USPS allows which is 6 1/8 inches. We also pack most items with in a bubble mailer, and a fragile sticker is added.