By Hansi Lo Wang – NPR
(NPR) Changes at the U.S. Postal Service are forcing people who rely on postmarks when voting, filing taxes or mailing legal documents to be extra careful when cutting it close to deadlines.
Postmarks include the dates that USPS stamps on envelopes, and those are often used to determine whether a piece of first-class mail was sent on time.
But the Postal Service has proposed revising its mailing standards to…




