Web Monitoring with sms warning

<?php
function checkURL($url) {

    //array of emails to send warning
    $adminEmails=array("admin1@t-zones.sk","admin2@vodafonemail.cz");
    //email of sender
    $senderEmail="monitoring@domain.tld";
    //array of valid http codes
    $validStatus=array(200,301,302);
    //minimum filesize in bytes
    $minFileSize=500;

    if(!function_exists('curl_init')) die("Curl PHP package not installed!");

    $ch=curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_HEADER, true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    $response=curl_exec($ch);
    $info=curl_getinfo($ch);
    $statusCode=intval($info['http_code']);
    $filesize=$info['size_download'];

    if(!in_array($statusCode,$validStatus) || $filesize<$minFileSize) {
        $message = "Web ERROR ($url) - Status Code: $statusCode, Filesize: $filesize\r\n";
        foreach($adminEmails as $email) {
            mail($email, "Web Monitoring ERROR", $message, "From: $senderEmail\r\nReply-To: $senderEmail\r\nMIME-Version: 1.0\r\nContent-Type: text/plain; charset=UTF-8\r\n");
        }
    }
}

checkURL("http://google.com/");
?>