Actually, Mississippi is one of eight states that still has "alienation of affection" laws still in effect. All other states abolished them. You really need to check how your state applies the law. Basically, these are laws from the past when wives were considered property and "stealing" them was actionable. Later, women were allowed to file suit also. And, check w/a lawyer, it will not be a cheap lawsuit.
Is it worth it? Your spouse is the one who cheated & you divorced. Move on. Punishing someone else isn't going to make your life better.