Question: My son is insisting that I can send him postcards to his name and 9-digit ZIP code, with no street address included. I don’t believe him. What’s the story and how do ZIP+4 ZIP codes work?

Norfolk, Va. – Effective immediately, anyone sending mail to Navy mobile units must use a nine-digit ZIP code to ensure delivery, according to a message released by Secretary of the Navy Ray Mabus.

Nowadays, people don't send letters to one another when they want to catch up. You may get holiday or birthday cards from your parents, grandparents or other family members and friends, but for the ...