(a) Service of process may be made upon the foreign personal representative by certified mail, addressed to the last reasonably ascertainable address, requesting a return receipt signed by the addressee only. Notice by ordinary first-class mail is sufficient if certified mail service to the addressee is unavailable. Service may be made upon a foreign personal representative in the manner in which service could have been made under other laws of this State on either the foreign personal representative or the decedent immediately prior to death.
(b) If service is made upon a foreign personal representative as provided in subsection (a) of this section, the foreign personal representative shall be allowed at least 30 days within which to appear or respond.