Okla. Stat. tit. 42, § 42-204: Notice of lien - Mailing

The broker shall, within ten (10) days of recording its notice

of lien, either mail a copy of the notice of lien to the owner of

record on the commercial real estate by registered or certified mail

at the address of the owner stated in the written instrument on

which the claim for lien is based, or if no such address is given,

then to the address of the commercial real estate on which the claim

of lien is based. Mailing of the copy of the notice of lien is

effective when deposited in a United States mailbox with postage

prepaid. The broker’s lien shall be unenforceable if mailing or

service of the copy of notice of lien does not occur at the time and

in the manner required by this section.