Been mailing packages all over the country in Priority Rate boxes with the USPS since the war started, mailed over 1,000. I have never had a box go missing even overseas. I do use common sense. Write plainly, cover address with tape, tape well, never put anything on the label (customs labels where needed) that would indicate anything of valuable inside. But since I have also worked at the USPS. And trust me, you would not believe what we saw that was considered "acceptable" by customers!! Jeez!