In connection with the sale of real estate under execution, the selling officer must publish the notice of sale for three consecutive weeks in the newspaper, or post notice of the sale in three public places in the county, one of which must be the courthouse door if notice by publication cannot be effected. See TEX. R. CIV. P. 647. The officer also must provide sale notice either by mail or in person to the judgment debtor or his attorney. See id. The officer is not liable for damages resulting from the execution of a writ issued by a court of this state if the officer: (1) in good faith executes the writ as provided by law and by the Texas Rules of Civil Procedure; (2) uses reasonable diligence in performing his official duties. See 7.003(a) (Vernon 1986).