Willie, mail gets delivered faster with planes.. Why do you think that DHL, USPS, UPS and FedEx uses planes..
Air is OK for transcontinental mail delivery. But short hop flights are too inefficient and expensive. And the trucks are too slow for regional service. High speed rail would fill the regional niche between air and truck service, making mail delivery even more quick and efficient.
Willie old fashioned mail is going away, thanks to email and faxes.. People can get the packages faster via truck and to a processing center much faster via truck for the short hops.. No need to spend trillions to prop up old technology..