Cook the elbow macaroni according to package instructions.
Drain, rinse, and set aside until it is room temperature.
In a small bowl, mix the mayonnaise, sour cream, mustard, and salt.
Set aside. (If you are assembling the salad later, be sure to refrigerate the dressing).
In a large container, add the cooked elbow macaroni, peas and carrots, corn, ham, and dressing.
Mix thoroughly.
Place in the refrigerator for 1 hour before serving.
Serve with saltine crackers.