Can you provide a URL to anything describing this as a formally supported process? It's inconsistent with my experience. I've had rural USPS staff become acce

Can you provide a URL to anything describing this as a formally supported process? It's inconsistent with my experience. I've had rural USPS staff become accepting of my non-USPS delivered packages as a personal favor, but never any sort of formalized process. The formal path is the $78/yr PO BOX, otherwise they're oftentimes downright hostile towards accepting non-USPS deliveries freely for randoms. Are you just referring to USPS-deliveries? That's different, since postage is being paid.