PHPMailer save emails to IMAP folder

example.php

<?php

include("Mailer.php");

$mail = new Mailer();
$mail->isSMTP(); // Tell PHPMailer we're going to use SMTP
$mail->Host = 'mail.localhost'; // Set SMTP host
$mail->Username = 'noreply@localhost'; // Set the our email address
$mail->Password = 'YourPassword'; // Set email address password
$mail->From = "[email protected]"; // The sender's email
$mail->FromName = "John Doe"; // The sender's name
$mail->addAddress("recipient@localhost"); // Recipient's email
$mail->addReplyTo($mail->From, $mail->FromName); // Add a reply to
$mail->Subject = "Mail for you!"; // Message subject
$mail->Body    = "Your message contents..."; // Message contents
if($mail->send()) { // Attempt to send the email
    $mail->copyToFolder(); // Will save into inbox
    $mail->copyToFolder("Sent"); // Will save into Sent folder
} else {
    echo "An error occurred, failed to send the email";
}

Mailer.php

<?php

class Mailer extends PHPMailer {

    /**
     * Save email to a folder (via IMAP)
     *
     * This function will open an IMAP stream using the email
     * credentials previously specified, and will save the email
     * to a specified folder. Parameter is the folder name (ie, Sent)
     * if nothing was specified it will be saved in the inbox.
     *
     * @author David Tkachuk <http://davidrockin.com/>
     */
    public function copyToFolder($folderPath = null) {
        $message = $this->MIMEHeader . $this->MIMEBody;
        $path = "INBOX" . (isset($folderPath) && !is_null($folderPath) ? ".".$folderPath : ""); // Location to save the email
        $imapStream = imap_open("{" . $this->Host . "}" . $path , $this->Username, $this->Password);

        imap_append($imapStream, "{" . $this->Host . "}" . $path, $message);
        imap_close($imapStream);
    }

}