Md. Code, Courts and Judicial Proceedings § 6–303

(a) If a person resists service of civil process by threats, violence, or superior force, or by preventing the officer serving the process from entering the premises so that the officer cannot serve the process without force or personal risk, the officer shall leave a copy of the process:

(1) With a responsible person at the premises; or if that is not possible

(2) Posted as near the premises as practicable.

(b) Service under this section is as effective as actual personal service.