That box should be free if they are not delivering to your house. I have that situation, except I live 2 blocks away.
I had to drive 40 miles for 6 months to get my mail 5 years ago when the post office was closed. Now I have to drive almost 40 miles in the opposite direction to get my mail. This has been going on over 7 months this time. There were 17 hostile workplace complaints filed against the postmaster in charge which they seemed to ignore so not much is being done.