I can't get this table to center align in outlook, can anyone help


<!doctype html>

<html>

      <table width="550px" height="136px" cellspacing="20px " style="font-style:normal; font-family:Arial, Helvetica, sans-serif; mso-ascii-font-family: Arial, Helvetica, sans-serif; color:#000; font-size: 10.53pt; background-color: #e6e6e6; margin:auto; text-align: center; height:136px;" >

    <tr>
      <td colspan="4" style="padding: 15px;">
        <table cellspacing="15" style="width:100%;">
          <tr height="50px";>
            <td width="50px" style="text-align: center;width:50px;  mso-ascii-font-family: Arial, Helvetica, sans-serif;">Login:</td>
            <td width="200px" style="text-align: center; background-color: #fff; color: #7e7e7e;width:200px; mso-ascii-font-family: Arial, Helvetica, sans-serif; padding: 10px;">###</td>
            <td width="75px" style="text-align: center;width:75px; mso-ascii-font-family: Arial, Helvetica, sans-serif;">Password:</td>
            <td width="200px" style="text-align: center; background-color: #fff; color: #7e7e7e;width:200px; mso-ascii-font-family: Arial, Helvetica, sans-serif; padding: 10px;">###</td>
          </tr>
        </table>
      </td>
    </tr>

    <tr>
      <td colspan="4">
        <table style="width:100%;">
          <tr height="50px">
              <td></td>
            <td bgcolor="#9f1b32" style="width:200px; color: #fff;font-weight: bold; font-size:12px;text-align:center;text-decoration:none; mso-ascii-font-family: Arial, Helvetica, sans-serif; padding: 12px;">RENEW NOW ></td>
              <td></td>
          </tr>
        <tr>
            <td><br>
            </td>
        </tr>
        </table>
      </td>
    </tr>

  </table> 


</html>