Phpnuke Newsletter Sending Problems

[BOAW 0]

i have a problem sending newsletters....when i send them no1 receives it...i tried sending to the registered users on my site which im in and i didnt recieve it in my mail...i dont know why this is happening...it says the newsletter is sent...but we get nothing in our mail... heres the code

<?php
/************************************************************************/
/* PHP-NUKE: Web Portal System */
/* =========================== */
/* */
/* Copyright © 2005 by Francisco Burzi */
/* https://www.phpnuke.org/ */
/* */
/* This program is free software. You can redistribute it and/or modify */
/* it under the terms of the GNU General Public License as published by */
/* the Free Software Foundation; either version 2 of the License. */
/************************************************************************/

if (!defined('ADMIN_FILE')) {
die ("Access Denied");
}

global $prefix, $db, $admin_file;
$aid = substr("$aid", 0,25);
$row = $db->sql_fetchrow($db->sql_query("SELECT radminsuper FROM " . $prefix . "_authors WHERE aid='$aid'"));
if ($row['radminsuper'] == 1) {

/*********************************************************/
/* Sections Manager Functions */
/*********************************************************/

function newsletter() {
global $prefix, $user_prefix, $db, $sitename, $admin_file;
include("header.php");
GraphicAdmin();
$srow = $db->sql_numrows($db->sql_query("select * from " . $user_prefix . "_users where newsletter='1'"));
$urow = $db->sql_numrows($db->sql_query("select * from " . $user_prefix . "_users"));
$urow--;
OpenTable();
echo "<center><font class=\"title\"><b>" . _NEWSLETTER . "</b></font></center>";
CloseTable();
echo "<br>";
OpenTable();
echo "<center><font class=\"content\"><b>" . _NEWSLETTER . "</b></font></center>"
."<br><br>"
."<form method=\"post\" action=\"".$admin_file.".php\">"
."<b>From:</b> $sitename"
."<br><br>"
."<b>" . _SUBJECT . ":</b><br><input type=\"text\" name=\"subject\" size=\"50\">"
."<br><br>"
."<b>" . _CONTENT . ":</b><br><textarea name=\"content\" cols=\"70\" rows=\"15\"></textarea>"
."<br><br>"
."<b>" . _WHATTODO . "</b><br>"
."<input type=\"radio\" name=\"type\" value=\"newsletter\" checked> " . _ANEWSLETTER . " ($srow " . _SUBSCRIBEDUSERS . ")<br>"
."<input type=\"radio\" name=\"type\" value=\"massmail\"> " . _MASSMAIL . " ($urow " . _USERS . ")"
."<br><br>"
."<input type=\"hidden\" name=\"op\" value=\"check_type\">"
."<input type=\"submit\" value=\"" . _PREVIEW . "\">"
."</form>";
CloseTable();
include("footer.php");
}

function check_type($subject, $content, $type) {
global $user_prefix, $db, $sitename, $admin_file;
include("header.php");
GraphicAdmin();
$srow = $db->sql_numrows($db->sql_query("select * from " . $user_prefix . "_users where newsletter='1'"));
$urow = $db->sql_numrows($db->sql_query("select * from " . $user_prefix . "_users"));
$urow--;
OpenTable();
echo "<center><font class=\"title\"><b>" . _NEWSLETTER . "</b></font></center>";
CloseTable();
echo "<br>";
OpenTable();
$content = stripslashes($content);
if ($type == "newsletter") {
echo "<center><font class=\"content\"><b>" . _NEWSLETTER . "</b></font>"
."<br><br>"
."<form action\"".$admin_file.".php\" method=\"post\">"
."" . _NYOUAREABOUTTOSEND . "<br>"
."<b>$srow</b> " . _NUSERWILLRECEIVE . "<br><br>"
."<b>" . _REVIEWTEXT . "</b></center><br><br>"
."<b>" . _FROM . ":</b> $sitename<br><br>"
."<b>" . _SUBJECT . ":</b><br><input type=\"text\" name=\"title\" value=\"$subject\" size=\"50\"><br><br>"
."<b>" . _CONTENT . ":</b><br><textarea name=\"content\" cols=\"70\" rows=\"15\">$content</textarea><br><br><br><br>"
."<b>" . _NAREYOUSURE2SEND . "</b><br><br>"
."<input type=\"hidden\" name=\"op\" value=\"newsletter_send\">"
."<input type=\"submit\" value=\"" . _SEND . "\">    " . _GOBACK . ""
."</form>";
} elseif ($type == "massmail") {
echo "<center><font class=\"content\"><b>" . _MASSEMAIL . "</b></font>"
."<br><br>"
."<form action\"".$admin_file.".php\" method=\"post\">"
."" . _MYOUAREABOUTTOSEND . "<br>"
."<b>$urow</b> " . _MUSERWILLRECEIVE . "<br>"
."<i><b>" . _POSSIBLESPAM . "</b></i><br><br>"
."<b>" . _REVIEWTEXT . "</b></center><br><br>"
."<b>" . _FROM . ":</b> $sitename<br><br>"
."<b>" . _SUBJECT . ":</b><br><input type=\"text\" name=\"title\" value=\"$subject\" size=\"50\"><br><br>"
."<b>" . _CONTENT . ":</b><br><textarea name=\"content\" cols=\"70\" rows=\"15\">$content</textarea><br><br><br><br>"
."<b>" . _MAREYOUSURE2SEND . "</b><br><br>"
."<input type=\"hidden\" name=\"op\" value=\"massmail_send\">"
."<input type=\"submit\" value=\"" . _SEND . "\">    " . _GOBACK . ""
."</form>";
}
if (($type == "newsletter") AND ($srow > 500)) {
CloseTable();
echo "<br>";
OpenTable();
echo "<center><i>" . _MANYUSERSNOTE . "</i></center>";
} elseif (($type == "massmail") AND ($urow > 500)) {
CloseTable();
echo "<br>";
OpenTable();
echo "<center><i>" . _MANYUSERSNOTE . "</i></center>";
}
CloseTable();
include("footer.php");
}

function newsletter_send($title, $content) {
global $user_prefix, $sitename, $db, $nukeurl, $adminmail, $admin_file;
$send_html_messages = "yes";
$from = $adminmail;
$subject = "[$sitename Newsletter]: " . stripslashes($title) . "";
$content = stripslashes($content);
$content = "$sitename " . _NEWSLETTER . "\n\n\n$content\n\n- $sitename " . _STAFF . "\n\n\n\n\n\n" . _NLUNSUBSCRIBE . "";
$result = $db->sql_query("SELECT user_email from " . $user_prefix . "_users where newsletter='1'");
while ($row = $db->sql_fetchrow($result)) {
$user_email = $row['user_email'];
$xheaders = "From: " . $sitename . " <" . $adminmail . ">\n";
$xheaders .= "X-Sender: <" . $adminmail . ">\n";
$xheaders .= "X-Mailer: PHP\n"; // mailer
$xheaders .= "X-Priority: 6\n"; // Urgent message!
if ($send_html_messages == "yes") {
$xheaders .= "Content-Type: text/html; charset=iso-8859-1\n"; // Mime type
}
mail("$user_email","$subject","$content",$xheaders);
}
Header("Location: ".$admin_file.".php?op=newsletter_sent");
}

function newsletter_sent() {
include("header.php");
GraphicAdmin();
OpenTable();
echo "<center><font class=\"title\"><b>" . _NEWSLETTER . "</b></font></center>";
CloseTable();
echo "<br>";
OpenTable();
echo "<center><font class=\"content\"><b>" . _NEWSLETTER . "</b></font><br><br>";
echo "<b>" . _NEWSLETTERSENT . "</b></center>";
CloseTable();
include("footer.php");
}

function massmail_send($title, $content) {
global $user_prefix, $sitename, $db, $nukeurl, $adminmail, $admin_file;
$send_html_messages = "yes";
$from = $adminmail;
$subject = "[$sitename]: $title";
$content = stripslashes($content);
$content = "" . _FROM . ": $sitename\n\n\n\n$content\n\n\n\n- $sitename " . _STAFF . "\n\n\n\n" . _MASSEMAILMSG . "";
$result = $db->sql_query("SELECT user_email from " . $user_prefix . "_users where user_id != '1'");
while ($row = $db->sql_fetchrow($result)) {
$user_email = $row['user_email'];
$xheaders = "From: " . $sitename . " <" . $adminmail . ">\n";
$xheaders .= "X-Sender: <" . $adminmail . ">\n";
$xheaders .= "X-Mailer: PHP\n"; // mailer
$xheaders .= "X-Priority: 6\n"; // Urgent message!
if ($send_html_messages == "yes") {
$xheaders .= "Content-Type: text/html; charset=iso-8859-1\n"; // Mime type
}
mail("$user_email","$subject","$content",$xheaders);
}
Header("Location: ".$admin_file.".php?op=massmail_sent");
}

function massmail_sent() {
include("header.php");
GraphicAdmin();
OpenTable();
echo "<center><font class=\"title\"><b>" . _MASSEMAIL . "</b></font></center>";
CloseTable();
echo "<br>";
OpenTable();
echo "<center><font class=\"content\"><b>" . _MASSEMAIL . "</b></font><br><br>";
echo "<b>" . _MASSEMAILSENT . "</b></center>";
CloseTable();
include("footer.php");
}

switch ($op) {

case "newsletter":
newsletter();
break;

case "newsletter_send":
newsletter_send($title, $content);
break;

case "newsletter_sent":
newsletter_sent();
break;

case "massmail_send":
massmail_send($title, $content);
break;

case "massmail_sent":
massmail_sent();
break;

case "check_type":
check_type($subject, $content, $type);
break;

}

} else {
echo "Access Denied";
}

?>

heopfully somebody can spot something out that may be the problem