Items sent through the mail must be packed in a way that prevents their
deterioration or degradation. Large-volume mailers should test before
shipping to determine their packaging's effectiveness and the product's
Mailers can use the International Safe Transit Association (ISTA) Test
Procedure 1A to evaluate their packaging (see Appendix A). Mailers can also
contact the nearest postmaster, account representative, or business mail
entry manager for a review of their packaging.