Yet, I note that each day we deliver more pounds of milk than mail. Further, milk is more perishable than a love letter, a catalogue, or an appeal for funds…the delivery of milk is more prompt and less costly to us than is the delivery of mail.
I ask myself, then, why shouldn’t private enterprise deliver mail? Private enterprise delivers freight.
https://mises.org/wire/no-we-dont-need-government-post-office