Pur prelevando la mail salvata in un file a parte, incontro lo stesso problema...

Qui tutto il codice...

codice:
<?php 
    session_start();
    
    //prelevo mail
    $fp = fopen("../../../dataForm.txt", "r");
    $data = fread($fp, 16);

    $my_email =$data;
    $errors = '';
    $name = '';
    $visitor_email = '';
    $user_message = '';
    fclose($fp);

    if(isset($_POST['submit'])) {
        
        $name = $_POST['name'];
        $visitor_email = $_POST['email'];
        $user_message = $_POST['message'];
        ///------------Do Validations-------------

        if(empty($name)) {
            $errors .= "<span style=\"color:red\"> Completa il campo Nome!!! </span>";
        }
        if(empty($visitor_email)) {
            $errors .= "<span style=\"color:red\">\n Completa il campo Mail!!! </span>";
        }    
        if(empty($user_message)) {
            $errors .= "<span style=\"color:red\">\n Completa il campo Messaggio!!! </span>";
        }                
        
        if(IsInjected($visitor_email)) {
            $errors .= "<span style=\"color:red\">\n Mail NON valida!!! </span>";
        }
        if(empty($_SESSION['6_letters_code'] ) || strcasecmp($_SESSION['6_letters_code'], $_POST['6_letters_code']) != 0) {
            $errors .= "<span style=\"color:red\">\n Codice captcha incorretto o non inserito!!! </span>";
        }
        
        if(empty($errors)) {
            //send the email
            $to = $my_email;
            $subject="Mail da $name";
            $from = $visitor_email;
            $ip = isset($_SERVER['REMOTE_ADDR']) ? $_SERVER['REMOTE_ADDR'] : '';
            
            $body ="$user_message\n".
            "\nIP: $ip\n";    
            
            $headers = "From: $from \r\n";
            $headers .= "Reply-To: $visitor_email \r\n";
            
            $sent=  mail($to, $subject, $body,$headers);
            if($sent) {            
                echo '<script type="text/javascript">document.location.href="thanks.html";</script>';
                    
            } else echo "Invio non riuscito";
        }
    }

    // Function to validate against any email injection attempts
    function IsInjected($str){
      $injections = array('(\n+)',
                  '(\r+)',
                  '(\t+)',
                  '(%0A+)',
                  '(%0D+)',
                  '(%08+)',
                  '(%09+)'
                  );
      $inject = join('|', $injections);
      $inject = "/$inject/i";
      if(preg_match($inject,$str)) {
        return true;
      } else {
        return false;
      }
    }
?>

Codice del form:
codice:
    <?php
        if(!empty($errors)){
        echo "<p class='err'> ".nl2br($errors)."</p>";
        }
        
    ?>

    <div id='contact_form_errorloc' class='err'></div>
    
    <form class="formMail" method="POST" name="contact_form" action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>"> 
        <p>
            <label for='name'>Nome: </label><br>
            <input type="text" placeholder="John Doe" name="name" value='<?php echo htmlentities($name) ?>'>
        </p>
        <p>
            <label for='email'>Email: </label><br>
            <input type="text" placeholder="mail@example.com" name="email" value='<?php echo htmlentities($visitor_email) ?>'>
        </p>
        <p>
            <label for='message'>Messaggio:</label> <br>
            <textarea name="message" placeholder="Write something to us" rows=8 cols=30><?php echo htmlentities($user_message) ?></textarea>
        </p>
        <p>
            <img src="../../captcha_code_file.php?rand=<?php echo rand(); ?>" id='captchaimg' ><br>
            <label for='message'>Inserisci il  codice captcha:</label><br>
            <input id="6_letters_code" name="6_letters_code" type="text"><br>
            <small>Impossibile leggere l'immagine? Clicca <a href='javascript: refreshCaptcha();'>QUI</a> per aggiornare</small>
        </p>
        <input type="submit" value="Submit" name='submit'>
    </form>
Ulteriori controlli:
codice:
    <script language="JavaScript">
        var frmvalidator  = new Validator("contact_form");

        frmvalidator.addValidation("name","req","Inserisci il tuo Nome"); 
        frmvalidator.addValidation("email","req","Inserisci la tua Mail"); 
        frmvalidator.addValidation("email","email","Inserisci una Mail Valida"); 
    </script>

    <script language='JavaScript' type='text/javascript'>
        function refreshCaptcha(){
            var img = document.images['captchaimg'];
            img.src = img.src.substring(0,img.src.lastIndexOf("?"))+"?rand="+Math.random()*1000;
        }
    </script>