Any Army wives out there?... how to keep baked goods fresh when mailing overseas?

[Mommy of 2?]

I'm sending a package over to my friend in Iraq. I want to include some cookies, muffins, stuff like that but I'm worried about them spoiling or going stale. How long should they keep in an air tight container? Would plastic bags work? Tin be better? Do you have any suggestions on cookies that last longer??? Thanks!

Originally had this in Food& Drink>> Cooking Recipes.... no one answered. Thanks!
Any **military** wives out there