Question with some backstory:
I have a friend who is currently thru-hiking the Appalachian Trail. As most do, he checks for mail at various post offices along the trail, where they'll hold packages for thru-hikers. I want to send him a package with stuff he needs (food mostly) but but maybe a surprise pick-me-up (read:a bottle or 2 of homebrew).
He said that the best thing to do is to use a USPS flat-rate box/envelope, because he can call in and "bounce" a package to a destination further up the trail if he can't get it or whatever.
I haven't looked into the sizes of those packages yet, but if a bottle could fit in to one -in a ziplock and wrapped in newspaper/bubblewrap- would there be a way that the USPS would know that I was mailing alcohol?
Any other general tips or previous experience?