symfony html mail via swift mailer

$mail_body = '<p>custom html mail content</p>';
$message = Swift_Message::newInstance('Message title')
        ->setFrom(array('sender'))
        ->setTo(array('receiver'))
        ->setBody($mail_body, 'text/html', 'utf-8');
 
try {
  $this->getMailer()->send($message);
}
catch(Exception $e) {
    // yay          
}