I'm assuming that taxes, fees, and other standardized costs are not considered harm, as well as other such incidental costs, otherwise no, nothing can be done by anyone that does not cause harm to someone else at the margin.
Mandating that the US postal service deliver to every address at a single price. This results in an efficient single price, efficiencies of scale that private carriers don't even have, and does not harm anyone outside of the externalities that would already exist for mail delivery regardless of who was doing the delivering.
Mandating that the US postal service deliver to every address at a single price. This results in an efficient single price, efficiencies of scale that private carriers don't even have, and does not harm anyone outside of the externalities that would already exist for mail delivery regardless of who was doing the delivering.