My post office has four blue mail collection bins out front. I frequently drop my mail there on my way to work, since my mail gets where it’s going about a day quicker than getting picked up at my house around noonish.
But they have two bins clearly marked “STAMPED MAIL” and two marked “METERED MAIL”. Netflix envelopes are business reply mail: they haven’t been marked by a meter machine, but I also don’t have to put stamps on them. I want to be a team player and help the post office out, but which one do you suppose they prefer?