Remember, the United States alone has half the mail in the world. That's because we have the world's most efficient and least costly mail system.
It doesn't get better than that even where private companies move the mail.
Not really sure about the amount, but surely it would be in the billions since that is constantly the amount given to the Post Office to continue operating.
Really just a guess..so I give you any question about amounts. Are you defending the idea that the Post Office moves lots of mail and loses money? And you are stating that a private company would lose more?