مساعدة في ملف PHP - خطأ بعد $siteOwnersEmail

آمل أن تكونوا بخير.

أواجه مشكلة في ملف PHP، وأبحث عن مساعدتكم، عندما أقوم باختباره عبر الإنترنت، يظهر لي خطأ بعد المتغير $siteOwnersEmail.

هل يمكنكم إرشادي حول كيفية ملء هذا الحقل بشكل صحيح؟

<?php

if($_POST) {

     $name = trim(stripslashes($_POST['contactName']));
     $email = trim(stripslashes($_POST['contactEmail']));
     $subject = trim(stripslashes($_POST['contactSubject']));
     $contact_message = trim(stripslashes($_POST['contactMessage']));

     // Check Name
     if (strlen($name) < 2) {
         $error['name'] = "Please enter your name.";
     }
     // Check Email
     if (!preg_match('/^[a-z0-9&\'\.\-_\+]+@[a-z0-9\-]+\.([a-z0-9\-]+\ .)*+[a-z]{2}/is', $email)) {
         $error['email'] = "Please enter a valid email address.";
     }
     // Check Message
     if (strlen($contact_message) < 15) {
         $error['message'] = "Please enter your message. It should have at least 15 characters.";
     }
     //Subject
     if ($subject == '') { $subject = "Contact Form Submission"; }


     // Set Message
     $message .= "Email from: " . $Name . "<br />";
     $message .= "Email address: " . $email . "<br />";
     $message .= "Message: <br />";
     $message .= $contact_message;
     $message .= "<br /> ----- <br /> This email was sent from your site's contact form. <br />";

     // Set From: header
     $from = $name . "<". $email . ">";

     // Email Headers
     $headers = "From: " . $from . "\r\n";
     $headers .= "Reply-To: ". $email . "\r\n";
     $headers .= "MIME-Version: 1.0\r\n";
     $headers .= "Content-Type: text/html; charset=ISO-8859-1\r\n";


     if (!$error) {

         ini_set("sendmail_from", $siteOwnersEmail); // for windows server
         $mail = mail($siteOwnersEmail, $subject, $message, $headers);

         if ($mail) { echo "OK"; }
         else { echo "Something went wrong. Please try again."; }
        
     } # end if - no validation error

     else {

         $response = (isset($error['name'])) ? $error['name'] . "<br /> \n": null;
         $response .= (isset($error['email'])) ? $error['email'] . "<br /> \n": null;
         $response .= (isset($error['message'])) ? $error['message'] . "<br />": null;
        
         echo $response;

     } # end if - there was a validation error

}

?>