Post Offices in San Mateo, California, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List 25th Avenue Post Office No Reviews Favorite Fax: (650) 349-9726Phone: (650) 358-8476Retail Hours Saint Matthew Post Office No Reviews Favorite Fax: (650) 349-9726Phone: (650) 358-8476Retail Hours San Mateo Post Office No Reviews Favorite Fax: (650) 349-9726Phone: (650) 358-8490Retail Hours