mail($email, "404 Alert: " . $blog . " [" . $theme . "]", $message, "From: $email");

<?php
// WP 404 ALERTS

// set status
header("HTTP/1.1 404 Not Found");
header("Status: 404 Not Found");

// site info
$blog = get_bloginfo('name');
$site = get_bloginfo('url') . '/';
$email = get_bloginfo('admin_email');

// theme info
if (!emptyempty($_COOKIE["nkthemeswitch" . COOKIEHASH])) {
$theme = clean($_COOKIE["nkthemeswitch" . COOKIEHASH]);
} else {
$theme_data = wp_get_theme();
$theme = clean($theme_data->Name);
}

// referrer
if (isset($_SERVER['HTTP_REFERER'])) {
$referer = clean($_SERVER['HTTP_REFERER']);
} else {
$referer = "undefined";
}
// request URI
if (isset($_SERVER['REQUEST_URI']) && isset($_SERVER["HTTP_HOST"])) {
$request = clean('http://' . $_SERVER["HTTP_HOST"] . $_SERVER["REQUEST_URI"]);
} else {
$request = "undefined";
}
// query string
if (isset($_SERVER['QUERY_STRING'])) {
$string = clean($_SERVER['QUERY_STRING']);
} else {
$string = "undefined";
}
// IP address
if (isset($_SERVER['REMOTE_ADDR'])) {
$address = clean($_SERVER['REMOTE_ADDR']);
} else {
$address = "undefined";
}
// user agent
if (isset($_SERVER['HTTP_USER_AGENT'])) {
$agent = clean($_SERVER['HTTP_USER_AGENT']);
} else {
$agent = "undefined";
}
// identity
if (isset($_SERVER['REMOTE_IDENT'])) {
$remote = clean($_SERVER['REMOTE_IDENT']);
} else {
$remote = "undefined";
}
// log time
$time = clean(date("F jS Y, h:ia", time()));

// sanitize
function clean($string) {
$string = rtrim($string);
$string = ltrim($string);
$string = htmlentities($string, ENT_QUOTES);
$string = str_replace("n", "
", $string);

if (get_magic_quotes_gpc()) {
$string = stripslashes($string);
}
return $string;
}

$message =
"TIME: " . $time . "n" .
"*404: " . $request . "n" .
"SITE: " . $site . "n" .
"THEME: " . $theme . "n" .
"REFERRER: " . $referer . "n" .
"QUERY STRING: " . $string . "n" .
"REMOTE ADDRESS: " . $address . "n" .
"REMOTE IDENTITY: " . $remote . "n" .
"USER AGENT: " . $agent . "nnn";

mail($email, "404 Alert: " . $blog . " [" . $theme . "]", $message, "From: $email");
?>