Okla. Stat. tit. 6, § 2119

Except as otherwise provided in this act, whenever the Commissioner is required to give notice to any applicant or licensee, such requirement shall be complied with if, within the time fixed herein, such notice shall be enclosed in an envelope plainly addressed to such applicant or licensee, at the address set forth in the application or license, United States postage fully prepaid, and deposited registered or certified in the United States mail.