Except for service of the summons and the original petition, service by mail is complete upon mailing, service by commercial carrier is complete upon delivery to the commercial carrier, and service by electronic means is complete upon transmission, unless the party making service is notified that the copy or paper served was not received by the party served. If the court clerk or a party is required to serve a judgment or other paper by first-class mail, service in accordance with any method permitted by this section is sufficient to comply with such requirement.
Okla. Stat. tit. 12, § 2005