Special characters (utf-8) in php contact message

I have a contact form. When I receive the message, I cannot read it normally because the special characters are shown strangely.

I saved my file in utf-8 without BOM, I am red and tried many variations on this but I could not find the correct answer for myself.

Contact form in my html:

<meta charset="utf-8" />
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 


<form id="contactform" action="processform.php" method="post" accept-charset='UTF-8'>
    <div class="form-label label-name">Nom</div>
    <input type="text" name="name" id="name" />
    <div class="form-label label-postcode">Code Postal</div>
    <input type="text" name="postcode" id="postcode" />
    <div class="form-label label-email">E-mail</div>
    <input type="text" name="email" id="email" />
    <div class="form-label label-subject">Sujet</div>
    <input type="text" name="subject" id="subject" />
    <div class="form-label label-message">Message</div>
    <textarea rows="4" name="message" id="message"></textarea>
    <input type="submit" id="send" name="button" value="Envoyer" />           
</form>

      

        
        
        
      

    

My processform.php file (saved in UTF-8 without BOM) has the following codes:

<?php

include_once $_SERVER['DOCUMENT_ROOT'] . '/securimage/securimage.php';

$securimage = new Securimage();

if ($securimage->check($_POST['verif']) == false) {
  // the code was incorrect
  // you should handle the error so that the form processor doesn't continue

  // or you can use the following code if there is no validation or you do not know how
  echo "Le code de s&eacute;curit&eacute; indiqu&eacute; est incorrect.<br />";
  echo "Rafra&icirc;chissez la page et essayez &agrave; nouveau svp.";
  exit;
}

// Clean up the input values
foreach($_POST as $key => $value) {
  if(ini_get('magic_quotes_gpc'))
    $_POST[$key] = stripslashes($_POST[$key]);

  $_POST[$key] = htmlspecialchars(strip_tags($_POST[$key]));
}

// Assign the input values to variables for easy reference
$name = $_POST["name"];
$email = $_POST["email"];
$subject = $_POST["subject"];
$message = $_POST["message"];

// Test input values for errors
$errors = array();
if(strlen($name) < 3) {
  if(!$name) {
    $errors[] = "Entrez votre nom svp.";
  } else {
    $errors[] = "Au moins 3 caractères sont requis pour un nom.";
  }
}
if(!$email) {
  $errors[] = "Entrez votre email svp.";
} else if(!validEmail($email)) {
  $errors[] = "Veuillez fournir une adresse valide svp.";
}
if(strlen($message) < 20) {
  if(!$message) {
    $errors[] = "Entrez un message svp.";
  } else {
    $errors[] = "Au moins 20 caractères sont requis pour un message.";
  }
}

if($errors) {
  // Output errors and die with a failure message
  $errortext = "";
  foreach($errors as $error) {
    $errortext .= "<li>".$error."</li>";
  }
  die("<span class='failure'>Les erreurs suivantes sont survenues :<ul>". $errortext ."</ul></span>");
}

// Remplacement de certains caractères spéciaux
header('Content-Type: text/html; charset=utf-8');

// Send the email
$to = "myemail@gmail.com";
$message = "
From: $name 
Email: $email 
Subject: $subject
Message: $message";
$headers = "Message from West Hungary website";

mail($to, $subject, $message, $headers);

// Die with a success message
die("<span class='success'>Votre message a &eacute;t&eacute; envoy&eacute; avec succ&egrave;s !</span>");

// A function that checks to see if
// an email is valid
function validEmail($email)
{
   $isValid = true;
   $atIndex = strrpos($email, "@");
   if (is_bool($atIndex) && !$atIndex)
   {
      $isValid = false;
   }
   else
   {
      $domain = substr($email, $atIndex+1);
      $local = substr($email, 0, $atIndex);
      $localLen = strlen($local);
      $domainLen = strlen($domain);
      if ($localLen < 1 || $localLen > 64)
      {
         // local part length exceeded
         $isValid = false;
      }
      else if ($domainLen < 1 || $domainLen > 255)
      {
         // domain part length exceeded
         $isValid = false;
      }
      else if ($local[0] == '.' || $local[$localLen-1] == '.')
      {
         // local part starts or ends with '.'
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $local))
      {
         // local part has two consecutive dots
         $isValid = false;
      }
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
      {
         // character not valid in domain part
         $isValid = false;
      }
      else if (preg_match('/\\.\\./', $domain))
      {
         // domain part has two consecutive dots
         $isValid = false;
      }
      else if(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
                 str_replace("\\\\","",$local)))
      {
         // character not valid in local part unless
         // local part is quoted
         if (!preg_match('/^"(\\\\"|[^"])+"$/',
             str_replace("\\\\","",$local)))
         {
            $isValid = false;
         }
      }
      if ($isValid && !(checkdnsrr($domain,"MX") || checkdnsrr($domain,"A")))
      {
         // domain not found in DNS
         $isValid = false;
      }
   }
   return $isValid;
}

?>