Three Area Post Offices Open Sunday12/14/2018 Three area post offices will be open Sunday to help with your Christmas mailings. Northwood, Waynedale, and Warsaw post offices will be open Sunday noon to four. Here are some mailing deadlines to ensure your gifts and cards arrive by Christmas. Today is the deadline for retail ground, December 20th for First Class and Priority Mail, and December 22nd for Priority Mail Express. More and more of you are shipping online at USPS dot com. You can print a shipping label, pay for postage, and ship your gifts without leaving home. The web site again: USPS dot com.