CSS/background-color/mail script problem

private_click

hello guys.
i have a little problem.i am currently working on a newsletter script for a website.everything seems fine except the backround of the newsletter.the "background-color" doesn't work, i'll give you the code that it's sent.

<head>
<style type="text/css">
a img {
  border: none;
  }
a:visited {
	text-decoration:none;
}
a:hover {
	text-decoration:none;
}
a:active {
	text-decoration:none;
}
body {
	background-color: #0f131f;
}
</style>
</head>
<body>
<span style="font-family:Tahoma ; font-size:11px ; color:#ffffff"><p>Header</p></span><br><br>

....bla bla some tables here not important stuff.....

<br><br><span style="font-family:Tahoma ; font-size:11px ; color:#ffffff"><p style="text-align: center;">&copy;COPYRIGHT&reg;</p></span></body>

and the headers for the mail are :

"To: To <$to_adress>\n" .
    	"From: From <newsletter@domain.com\n" .
    	"MIME-Version: 1.0\n" .
    	"Content-type: text/html; charset=iso-8859-1"

thx.

LE: it looks like yahoo doesn't support background-color in body.
i worked it around putting all in a table and changing the table background-color.