connecting to usenet with php?

So far, this script connects to the NNTP server, but it won't send the test message.. any idea why?

<?php
require_once "sss.php";

$nntp = new Net_NNTP;
$ret = $nntp->connect("news.usenetserver.com",119,"xxxxx","xxxxx");
if( PEAR::isError($ret)) {
echo "you are not connected"; exit;
} else {
echo "you are connected";

$subject = "Testpost";
$newsgroup = "alt.test";
$body = "Le Mardi 12 f=E9vrier 2002, this is a test message using special french chars";
$from = "test@example.com";
$addheader = "Content-Transfer-Encoding: quoted-printable\n".
"Content-Type: text/plain; charset=ISO-8859-1;";

$response = $nntp->post($subject, $newsgroup, $body, $from, $addheader);

if (!$response) { echo "<br>not sent"; } else {echo "message sent"; }

}

?>