Key holiday shipping deadlines and tips to avoid shipping scams

ST. LOUIS (KTVI) – The season of giving is also a season of shipping. Here are some companies' shipping deadlines you should know to make sure your package is delivered before Christmas, with some according to BlackFriday.com.Let’s start with the United States Postal Service. Retail ground and first-class mail should be sent by Dec. 17; for priority mail, ship by Dec. 19; and for priority express, the cut-off is Dec. 23.Over at UPS, Dec. 20 is your deadline for Three-Day Select; for