Okla. Stat. tit. 12, § 12-1148.5A: Constructive service of summons

If, in the exercise of reasonable diligence, service cannot be

made upon the defendant personally nor upon any person residing upon

the premises over fifteen (15) years of age, then in lieu of service

by certified mail, service may be obtained for the sole purpose of

adjudicating the right to restitution of the premises by the

sheriff's posting or by private process service posting of said

summons conspicuously on the building on the premises, and, if there

be no building on said premises, then by posting the same at some

conspicuous place on the premises sought to be recovered at least

five (5) days prior to the date of trial, and by the claimant's

mailing a copy of said summons to the last-known address of the

defendant by certified mail at least five (5) days prior to said

date of trial. Such service shall confer no jurisdiction upon the

court to render any judgment against the defendant for the payment

of money nor for any relief other than the restoration of possession

of the premises to the claimant, unless the defendant appears at

trial. If the court only renders a judgment for restoration of

possession of the premises, the claimant shall not be precluded from

pursuing a subsequent action for the payment of rent. A judgment

for forcible entry and detainer shall not preclude the property

owner from pursuing a subsequent action for other monetary relief.

Such service shall not be rendered ineffectual by the failure of the

defendant to actually see or receive such posted process nor by the

failure of the defendant to actually receive or sign a return

receipt for such mailed process.