$message = new Email();
        $message->html('text/html');
        $message->bcc($this->getAdminEmail());
        $message->to(new Address($user->getEmail(), $user->getDisplayName()))
            ->subject($subject)
            ->html($body)
        ;
        $signer = new DkimSigner('file://' . $dkimPath, $dkimDomain, 'mySelector');
        $signedMessage = $signer->sign($message);
        $this->mailer->send($signedMessage);