Post Offices in Caldwell, New Jersey, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List Caldwell Post Office No Reviews Favorite Phone: (973) 227-2699Retail Hours West Caldwell Post Office No Reviews Favorite Fax: (650) 577-4367Phone: (973) 227-2699Retail Hours