The Treasurer shall not be required to make personal demand for the payment of taxes but, upon receipt of the city tax roll, he shall, forthwith, mail a tax statement to each person named in the tax roll, which mailed statement shall be a sufficient demand for the payment of all taxes assessed. Neither the failure on the part of the Treasurer to mail such statement nor the failure of any person to receive the same, shall invalidate the taxes on the tax roll or release any person or property assessed from the liabilities provided in this Charter in case of nonpayment.