Once the complaint has been filed with the court, the court clerk will issue a "Writ of Summons" along with a copy of the complaint. Both documents must be served on the other spouse.
"Service of process" means that the other spouse receives a copy of the divorce paperwork. By Delivering these documents your spouse will be provided the required notice that the divorce has been filed in the courts.
Under Maryland law, the responding spouse may be served by receiving a copy of the complaint and the writ of summons from the following:
any person over the age of 18, other the other spouse
the county sheriff where the defendant lives or works (the sheriff will charge a fee for this service), or
a private process server, that will charge a fee.
If any of the above methods of service are unsuccessful, then a party may need to ask the Court to serve the other spouse by certified mail, return receipt requested. This means that the post office will require that the other spouse sign for the copy and the serving spouse will receive proof of delivery with the return of the receipt, which is the green card.