I can't see my neighbor's houses, but I still get their mail in my box. Maybe teaching their employees to read would fix the problem. You really shouldn't expect much from the USPS. Counting could also be a problem for them, or theft.
The thing is that most nations grasp that the mail system is supposed to be a service for the good of the nation and NOT a for profit operation. We need to go back to when the USPS was just that instead of it trying and failing to compete with UPS or other commercial services.