F9 took on mail sometime last year after they implemented some software (from MSFT IIRC) that made it profitable for them to do so. I sincerely hope that US didn't decide to upgrade their mail handling software instead of all their other software that desperately needs upgrading.
(Unless of course U.S. mail is some major profit center, more profitable than passengers)
(Unless of course U.S. mail is some major profit center, more profitable than passengers)