S.C. Code Ann. § 40-38-360

Notices required by this chapter may be sent by registered mail, return receipt requested, to the person's last mailing address furnished to the board. The post office registration receipt signed by the recipient, his agent, or a responsible member of his household or office staff or, if not accepted by the person to whom addressed, the postal authority stamp showing the notice refused is prima facie evidence of service of the notice.