The U.S. Postal Service's new postmark process could lead to late fees and penalties when mailing time-sensitive documents.

Walter Mondale, former vice president of the United States and U.S. Ambassador to Japan, and his wife Joan, member of the Citizens’ Stamp Advisory Committee, will lead a special first day of sale ...

Bird lovers are expected to flock to their Post Offices now that the Postal Service is celebrating North America’s largest swallow by issuing the Purple Martin First-Class Mail Forever Stamped ...