Okla. Stat. tit. 58, § 58-34: Mailing and proof of mailing - Persons authorized to make

When mailing is required by Section 21 et seq. of this title,

the mailing shall be made by the court clerk or a deputy court clerk

or by the attorney for the party and proof of the mailing shall be

by affidavit of the court clerk or deputy court clerk or attorney

filed in the case. Any mailing made pursuant to this section after

June 22, 1988, which is in compliance with the provisions of this

section at the time this act becomes effective, shall be deemed to

be in compliance with this section.