Ga. Code § 15-9-86
Every application made to the judge of the probate court for the granting of any order shall be by verified petition in writing, stating the ground of such application and the order sought. Unless otherwise provided by law, if service of notice of such petition, other than by citation published in the official newspaper of the county in which the petition is made, is necessary under the law or in the judgment of the judge of the probate court on the motion of any party in interest or on the court's own motion, the judge shall cause a copy of the petition, together with a citation to show cause, if any, why the petition should not be granted and notice of the date, time, and place for filing any objections or for holding a final hearing, to be served by the sheriff or some lawful officer upon each party who resides in this state and to be served by the probate court mailing by registered or certified mail or statutory overnight delivery, return receipt requested, to each party who resides outside this state at a known address, at least 30 days before any objection is required to be filed by such party or before a final hearing is held. An entry of such service of notice shall be made on the original. In extraordinary cases, where it is necessary to act before such service of notice can be given, the judge of the probate court shall so direct the proceedings as to make no final order until service of notice has been given.
OCGA § 15-9-86