added as per qa

mailContact.php

@@ -18,6 +18,11 @@ if ($_SERVER['REQUEST_METHOD'] == 'POST') {
     $subject = htmlspecialchars(trim($_POST['subject']));
     $message = htmlspecialchars(trim($_POST['message']));
 
+    if (!preg_match('/^[0-9]{10}$/', $_POST['phone'])) {
+    $errors[] = "Please enter a valid 10-digit phone number.";
+}
+
+
     if (!empty($name) && !empty($user_email) && !empty($phone) && !empty($subject) && !empty($message) && !empty($address)) {
         try {
             // Send confirmation email to user