Rule 5.1. Method.

 Except where otherwise provided by a rule adopted by the Supreme Court or by an Act of Assembly, whenever notice is to be given a person, it shall be given

   (a)  by service upon the attorney appearing of record for such person; or

   (b)  if there is no such attorney, by personal service, delivery at the residence of such person or by mail, if his residence is known; or

   (c)  if his residence is not known, by publication once a week during three successive calendar weeks in the legal periodical, if any, and in a newspaper of general circulation published at or near his last known residence within the county; or

   (d)  in such other manner as the court shall direct.