In Maryland:
"The Summons and Complaint are sent to the defendant by certified mail, restricted delivery, return receipt requested, unless you ask the sheriff to serve (deliver) the papers, or unless you wish to have the papers served by a private process server"--any person over 18 years old not directly involved in the case, who will deliver the papers personally and return to the Court an affidavit that he or she has completed service. If the Court or sheriff has attempted to serve the defendant without success, you will be notified. You may then, for an additional fee, renew the Summons and attempt to serve the defendant. You may decide to give the Court a different address for the defendant or try another method of service."
http://www.marylandlawonline.com/md/smallclaims/serclaim.htm
So, according to the above, you can return to the court and renew the Summons and have it served by any of the allowed methods.