Waarom kan ik deze layout

niet via een mail versturen:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 
<head>
<title>Mail systeem</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<style type="text/css">
body {
  background: url(http://supermails.nl/images/bg.PNG);
  font-family: verdana;
  font-size: 11px;
  margin: 0;
  color: #333333;
}
#logo {
  background: url(http://supermails.nl/images/logo.PNG);
  height: 109px;
  width: 382px;
}
.head {
  background: url(http://supermails.nl/images/mailhead.PNG);
  height: 24px;
  width: 544px;
  padding-top: 6px;
  padding-left: 5px;
  font-weight: bold;
  color: #ffffff;
  text-align: left;
}
.content {
  width: 547px;
  border: 1px solid #000000;
  border-top: 0px;
  background: #ffffff;
  margin-bottom: 10px;
  text-align: left;
}
</style>
</head>
<body>
<center>
    <div id="logo"></div>
    <div class="head">Test Mail</div>
    <div class="content">Test</div> 
</center>
</body>
</html>

Zal ik ook morgen voor je fixen Denk ik xD