Sending php mail, adding country code - php

Question

I add to country code input area but country code not included when sending mail. When you fill in your phone number, it looks like the picture in the picture 1 but I want you to look like the picture 2. How do I edit this in php mailer? The codes index.php and mail.php are below. (I corrected the picture by checking the item in order to be an example) If you need JS Code
http://allinoneinvest.com/landing/intlTelInput.js
Picture 1
Picture 2
index.php phone input code
<div class="lp-pom-form-field clearfix" id="container_phone">
<label for="phone" class="main lp-form-label" id="label_phone">Phone *</label><input type="tel" id="mobile-number" oninput="this.value = this.value.replace(/[^0-9+.]/g, '').replace(/(\..*)\./g, '$1');" name="phone" class="text form_elem_phone" required>
</div>
mail.php
<?php
if (isset($_POST["submit"])) {
$isimsoyisim = $_POST['your_name'];
$email = $_POST['your_email'];
$subject = $_POST['subject'];
$phone = $_POST['phone'];
$message = $_POST['message'];
require("class.phpmailer.php");
$mail = new PHPMailer();
$mail->IsSMTP();
$mail->SMTPDebug = 1;
$mail->SMTPAuth = true;
//$mail->SMTPSecure = 'tls';
$mail->Host = "mailhost";
$mail->Port = 587;
$mail->IsHTML(true);
$mail->SetLanguage("tr", "phpmailer/language");
$mail->CharSet ="utf-8";
$mail->Username = "mail";
$mail->Password = "mailpwd";
$mail->SetFrom("$email", "$isimsoyisim");
$mail->AddReplyTo("$email", "$isimsoyisim");
$mail->AddAddress("email");
$mail->Subject = "Landing Page - $isimsoyisim";
$mail->Body = "<strong>Message:</strong><br />$message <br /><br /><strong>Mail:</strong> $email<br /><br /><strong>Phone:</strong> $phone<br /><br /><br /><br /> This message was sent from the landing page";
if(!$mail->Send()){
echo "Error: ".$mail->ErrorInfo;
} else {
$gittiMesaji = "Dear $isimsoyisim Your Message Sent";
}
}
?>