Place the potatoes and salt in a large stockpot and cover with cold water.  Bring to a boil over high heat.  Reduce the heat to medium-low and cook for 15 to 20 minutes or until fork tender.  Drain and place the potatoes in a large mixing bowl.  Add cream cheese, sour cream, butter and milk.  Beat at  medium speed with an electric mixer until smooth and fluffy.  Season to taste with salt and pepper.  Serve immediately or store covered in the refrigerator and heat in the oven until 165 F.