def do_email_authors(self, comment, entry, site):
        """
        Send email notification of a new comment to
        the authors of the entry.
        """
        if not self.email_authors:
            return

        exclude_list = self.mail_comment_notification_recipients + ['']
        recipient_list = (
            set([author.email for author in entry.authors.all()])
            - set(exclude_list)
        )
        if not recipient_list:
            return

        template = loader.get_template(
            'comments/zinnia/entry/email/authors.txt')
        context = {
            'comment': comment,
            'entry': entry,
            'site': site,
            'protocol': PROTOCOL
        }
        subject = _('[%(site)s] New comment posted on "%(title)s"') % \
            {'site': site.name, 'title': entry.title}
        message = template.render(context)

        send_mail(
            subject, message,
            settings.DEFAULT_FROM_EMAIL,
            recipient_list,
            fail_silently=not settings.DEBUG
        )
Send email notification of a new comment to
        the authors of the entry.