What if the other party can not be served?

You cannot serve him yourself, but you can serve him at work. If you have already had a summons issued by the clerk, take the summons, a copy of the summons, and a copy of whatever you want served to a process server.

The method of service required will depend on the type of proceeding that you have scheduled for hearing. No-you can not "serve" your former husband. That must be done by someone properly authorized, such as a sheriff's deputy or process server. However, if you have any information regarding his physical whereabouts, such as when he is at work, and where he is working, service could be made at that location. If you know where he is working, provide that information to a private process server, along with a photograph and a description of his vehicle. That will increase probability of tracking him down. Good luck!

I agree with the previous submissions. I strongly encourage you to seek legal counsel in your area. Although I don't know your circumstances, service is generally one of the more straight forward matters in a case. I expect that you are going to have many other questions during litigation and would likely benefit from legal assistance.

No, you have to have lawful service of process. You should check with your lawyer or the process server to see if they can catch him at work or someplace to effect personal service.

You have to use a process server. Serve him at work. Use of a lawyer is recommended.