42 Pa.C.S. § 8385: Service of original process.

(a) General rule.--A copy of the summons and complaint shall be served upon the defendant at least five business days prior to the first hearing in the action. Service of original process shall be made in accordance with the Pennsylvania Rules of Civil Procedure.

(b) Posting at property.--If personal service cannot be made, service may be made by posting the papers at the property. If service is made by posting at the property, a copy of the summons and complaint shall be mailed registered mail to the last known mail address, if any, of the defendant. Actual receipt of the registered mail shall not be required for service.