The Treasurer shall not be required to make personal demand for the payment of taxes, but, upon receipt of the City tax roll by him, he shall forthwith mail a tax statement to each person named in the tax roll and shall give at least six days' notice of the date upon which City taxes are due, by publication in a newspaper of the City, which notice shall be sufficient demand for the payment of all taxes assessed in the City tax roll. Neither the failure on the part of the Treasurer to give notice or to mail a tax statement, nor the failure of any person to receive the notice or the tax statement, shall invalidate the taxes on the tax roll or release any person or property assessed from the penalty provided in this chapter in case of nonpayment.