Thanks for the link - the 6x in pricing is to enforce the monopoly on delivery of letters rather than all mail items. It only applies to (i) items weighing less than 12.5oz (ii) to the first 1.0oz of a single piece of mail.
Certainly an enforcement of USPS' monopoly on letter delivery, but not a blanket price fixing across all mail items and types.
Certainly an enforcement of USPS' monopoly on letter delivery, but not a blanket price fixing across all mail items and types.