United States Postal Service (USPS). Track & trace the parcel from USA sent by USPS

USPS tracking service goes down after agency rolls out sweeping changes

USPS Certified Mail Rates, Mailing Costs | Simple Certified Mail

Affordable 2-5 day shipping with USPS Ground Advantage® service means you can count on us to deliver holiday joy. Exclusions apply. | US Postal Service

Reference our holiday shipping deadlines for expected delivery by Dec. 25. | US Postal Service

How to Become a Contract Delivery Service for the United States Postal Service

'Bad planning, lack of management and understaffing' | USPS shipping delays traced to Indy distribution hub