Post Offices in Costa Mesa, California, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List Costa Mesa Post Office No Reviews Favorite Fax: (714) 546-0325Phone: (714) 546-5022Retail Hours Mesa Center Post Office No Reviews Favorite Fax: (949) 646-4569Phone: (949) 646-2805Retail Hours