Does a sheriff have to serve divorce papers?

No, the sheriff does not have to serve divorce papers in every case. The sheriff is only one of the ways that you may serve your spouse with the divorce papers.  The easiest way to obtain service would be to have your spouse sign a document known as an Acceptance of Service (talk to your lawyer about preparing this document).  Other options may include delivery by certified mail (with return receipt), a designated delivery service (such as FedEx or UPS), or a private process server (an individual that hands the papers to your spouse).  Of course, if your spouse refuses to sign for or accept the documents, the best option may end up being the sheriff, but you would have given him the chance to avoid embarrassment by accepting service through another method.