Okla. Stat. tit. 58, § 58-26: Heirs, legatees, devisees and executors to be given notice

by mail.

Written or printed copies of the notice of the time appointed

for the probate of the will, must be addressed to the heirs,

legatees and devisees of the testator, at their places of residence,

if known to the petitioner, and deposited in the post office, with

the postage thereon prepaid by the petitioner, at least ten (10)

days before the hearing; the notice must be issued by the judge over

the seal of the court. Proof of the mailing of the notice must be

made at the hearing; the same notice and proof of service thereof on

the person named as executor must be made if he be not the

petitioner; also on any person named as coexecutor, not petitioning,

if his place of residence be known.