How to pack cookies so they don't crumble when mailing.
Purchase some pre-popped popcorn (or make your own). Put popcorn in small Ziploc bags and use them to line the box you will be using for mailing. Put your cookies in Ziploc bags and place on top of popcorn. Cover with another layer of popcorn bags. Your recipient won't have to deal with broken cookies and will have an extra treat of popcorn.