Refrigerate any leftover ham in individual servings. In the days after Christmas when your house is still full and your energy is waning, this will make it easy for guests to fix a meal on their own.
Preheat oven to 325°. Place ham, cut side down, on a lightly greased (with cooking spray) rack in a heavy-duty aluminum foil-lined broiler pan; let stand at room temperature 30 minutes.
Stir together preserves and next 3 ingredients in a saucepan. Bring to a simmer over medium-low heat. Simmer, stirring occasionally, 2 minutes. Remove from heat, and reserve 1 1/2 cups. Brush remaining glaze over ham.
Bake at 325°, uncovered, on lowest oven rack 2 hours or until a meat thermometer inserted in thickest portion registers 140°, basting every 30 minutes with reserved 1 1/2 cups glaze. Let stand 15 minutes before serving.