Even though many hams are precooked when you buy them, they will still benefit from being cooked. Baking a precooked ham will bring out its flavor and moistness and baking it slowly at a lower temperature with enhance it further. But, NEVER bake the ham below 200°F. No matter what temperature you bake it at, be careful to not overcook the ham or it will become dry and tough.
Cook ham safely to 140° F to intensify its flavor and juiciness.