Should a Pre-lien Notice Letter be notarized and filed with the Property Records?

No. The notices do not need to be notarized and should only be mailed to the Project Owner and the General Contractor through the U.S. Postal Service. However, they must be sent Via Return Receipt Requested (RRR) and the sender should retain the receipt as proof.
Texas Easy Lien also recommends to all sub-subcontractors (2nd Tier contractors) to send a copy of these notices to all subcontractors above involved.