O.C.G.A. § 53-5-46: Service of process.

(a) Service of process may be made upon the personal representative of a decedent who dies domiciled outside this state by registered or certified mail, addressed to the personal representative’s last reasonably ascertainable address, requesting a return receipt signed by the addressee only. Service of process upon such a personal representative may also be perfected by statutory overnight delivery as provided in Code Section 9-10-12 if the receipt provided by the commercial delivery company is signed by the addressee. Notice by first-class mail is sufficient if certified or registered mail service to the addressee is unavailable. Service may be made upon the personal representative in the manner in which service could have been made under other laws of this state on either the personal representative or the decedent immediately prior to death.

(b) If service is made on the personal representative as provided in subsection (a) of this Code section, the personal representative shall be allowed at least 30 days within which to appear and respond.