Notice, as prescribed in section 43-2-60, must be given:
(1) By first-class mail addressed to their last known address, or by other mechanism reasonably calculated to provide actual notice, to all persons, firms, and corporations having claims against the decedent, who are known or who are reasonably ascertainable by the personal representative within six months from the grant of letters; and
(2) By publishing a notice once a week for three successive weeks in a newspaper of general circulation published in the county in which the letters were granted or, if none is published in the county, in the one published nearest to the courthouse thereof or in an adjoining county.