S.C. Code Ann. § 36-2-806

(1) When the law of this State authorizes service outside this State, the service, when reasonably calculated to give actual notice, may be made: (a) by personal delivery in the manner prescribed for service within the State; (b) in the manner prescribed by the law of the place in which the service is made for service in that place in an action in any of its courts of general jurisdiction; (c) by registered or certified mail as provided in Rule 4(d)(8) of the South Carolina Rules of Civil Procedure addressed only to the person to be served and requiring a return receipt showing the acceptance by the defendant. Entry of default and default judgments shall be subject to the conditions of Rule 4(d)(8); or (d) as directed by the court. (2) Proof of service outside this State may be made by affidavit of the individual who made the service or in the manner prescribed by law of this State, the order pursuant to which the service is made, or the law of the place in which the service is made for proof of service in an action in any of its courts of general jurisdiction. When service is made pursuant to item (c) of subsection (1) of this section, proof of service shall include a receipt signed by the addressee.