Can You Get a Divorce Without Serving the Other Party

My question involves a marriage in the state of: mississippi also louisiana, we go back and for to both states due to his job. He has been married to another woman since
before I met him. They were not together because she abused him and left him for another man. She has mental problems and he hasn't wanted to deal with her. I've been with him 12 years now and we have a 9 year old son. I'm tired of waiting for him to get his divorce because we want to be married. His ex lives in mississippi and they haven't seen each other in over 12 years. we do not know where she lives and have no way of contacting her. She did send a message back through his daughter about a year ago saying she would never give him a divorce. They have no property, no children and nothing that should keep them from getting a divorce. She is really bitter at him and just seems to want revenge. Like i said she is mental. She is on SSD due to her mental state and she has always told him that she would fight him for alimony and take all he has. I heard that in Ms state you can run an ad in the news paper and if she doesn't respond in a certain amount of time then he would be able to get his divorce without having to fight with her. I don't know what to do. I've been with him for 12 years and I am going to grow old with him. He is my heart as i am his. What would be the easiest way to get this divorce over with? Is there any way we can get this done without having to see her. She is hateful and crazy and we really don't want to have to deal with her if at all possible. They have nothing to fight over other than her saying she's going to get him for alimony. I would think that if she has been able to take care of herself for the
last twelve years then i don't understand why she wants to fight him for this after all of this time. She's just really mean and hateful and i would love to be able to do this the easy route. We have money to pay for the divorce but we just don't really know how to go about it. Please Help !!!

My ex husband was upset when I finally insisted on a divorce (after being separated for several years) He'd used our marriage as an excuse not to commit to his new lady. (yes, he told me that)

He has to serve her. He is not going to be permitted to divorce her by substituted service unless he makes a bona fide, diligent effort to effect actual service. As for whether or no the spouse participates in court proceedings, that's up to her.