I doubt that "too hard" is really the issue here. yeah, if USPS wanted to figure it out, i'm sure they could. but what actually happens is that the USPS contr

I doubt that "too hard" is really the issue here. yeah, if USPS wanted to figure it out, i'm sure they could. but what actually happens is that the USPS contracts somebody else to figure it out for them, and that contractor charges USPS a price for that. if the price is worth it, USPS pays. if the price isn't worth it, then USPS stops delivering there.