You know those crackpot ideas that keep showing up in snake oil crypto? Well, e-postage is snake oil antispam.
While I think this statement may be true for POW coinage, because for a bot net it “grows on trees”, for money that traces back to the international monetary exchange system, it may not be completely true.
Snail mail postage limits, but does not eliminate junk mail. I think, without proof, that most people can live with the amount of junk mail they receive. At least I don’ hear a lot of conversations about the “Junk mail problem”.
Now it is certainly true that if machines have a small amount of money stored within them for “postage”, someone who 0wns that machine could steal some of that money. There is a limit to the amount that can be stolen based on the person who pays for the machine noticing and being bothered. There is probably safe profit in skimming small amounts from large number of machines just like there was profit in skimming the round off in payroll calculations.
Cheers - Bill