S.C. Code § 15-9-450
Service, upon any individual nonresident executor, administrator, guardian, conservator, or trustee, of any claim, demand, debt, dues, summons, or any other process, or pleading in suits or actions relating to the administration of the estate in his charge may be made upon the resident of this State appointed by such fiduciary as his agent for such purpose pursuant to the provisions of the South Carolina Probate Code or, in the event of the death, removal, resignation or absence from the State of such agent, or the inability of the person desiring to serve such agent so to do for any other reason, then upon the probate judge or the clerk of the court of common pleas of the county wherein the application of such fiduciary for appointment was made.
S.C. Code § 15-9-450