Post Offices in Ronkonkoma, New York, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List Lake Ronkonkoma Post Office No Reviews Favorite Fax: (631) 471-1290Phone: (631) 588-1292Retail Hours Ronkonkoma Post Office No Reviews Favorite Fax: (631) 471-1290Phone: (631) 588-0301Retail Hours