does anyone know, how a simple test like bellow, can fail looking it on iphone4s for example? im sending with interspire email marketer, latest version.

no matter what i try, it just doesnt trigger the responsive media query. html code i use for test is:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html>
<head>
  <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
<meta charset="UTF-8">
<style type="text/css">
@media only screen and (max-device-width: 480px) {
table[class=tableContent] {
width:320px !important;
font-size:50px !important;
line-height:50px !important;
}
}
</style>
<title>responsive test</title>
</head>

<body bgcolor="#EAE8E4" topmargin="0" leftmargin="0" marginheight="0" marginwidth="0" style="height: auto; padding:0; margin:0; -webkit-text-size-adjust:none; -ms-text-size-adjust: 100%;">

<table cellspacing="0" cellpadding="0" border="0" align="center" width="700" class="tableContent">
  <tbody>
    <tr>
      <td bgcolor="#FFFFFF">
datum = 15.5.2014
      </td>
    </tr>
  </tbody>
</table>
</body>
</html>