Bring a large saucepan of lightly salted water to a boil. Add the macaroni then cook until tender, about 8 minutes. Drain and cool.
In a large bowl, mix together the mayonnaise, mustard, relish, olives, celery and spring onions. Mix in the macaroni and season with salt and pepper to taste. Add more mayonnaise if you like. For best flavour, cover and refrigerate overnight. Sprinkle with paprika just before serving.