def send_confirmation_email(self):
        """
        An email confirming that the order has been confirmed and that we are
        waiting for the payment confirmation if we are really waiting for it.

        For setting a convention this email has to be sent by rendering the
        templates
           * Text: `<module_name>/emails/sale-confirmation-text.jinja`
           * HTML: `<module_name>/emails/sale-confirmation-html.jinja`
        """
        EmailQueue = Pool().get('email.queue')
        Sale = Pool().get('sale.sale')
        Mail = Pool().get('mail.mail')

        if self.email_sent:
            return

        bcc_emails = self._get_bcc_emails()

        to_emails = self._get_receiver_email_address()
        if to_emails:
            sender = config.get('email', 'from')
            subject = self._get_subject_for_email()
            html_template, text_template = self._get_email_template_paths()
            template_context = self._get_email_template_context()

            email_message = Mail.render_email(
                from_email=sender,
                to=', '.join(to_emails),
                subject=subject,
                text_template=text_template,
                html_template=html_template,
                sale=self,
                **template_context
            )

            EmailQueue.queue_mail(
                sender, to_emails + bcc_emails,
                email_message.as_string()
            )

            Sale.write([self], {
                'email_sent': True,
            })