def METHOD_NAME(post):
    topic = post.topic
    old_lang = translation.get_language()
    # Define constants for templates rendering
    context_vars = {'delete_url': reverse('pybb:delete_subscription', args=[post.topic.id]),
                    'site_url': get_setting('site', 'global', 'siteurl'),
                    'is_new_topic': post == topic.head,
                    'post': post,
                    'post_url': reverse('pybb:post', args=[post.id]),
                    'forum_url': reverse('pybb:forum', args=[topic.forum.id]),
                    }
    from_email = settings.DEFAULT_FROM_EMAIL
    mails = tuple()
    if post == topic.head:
        subject_template = 'pybb/mail_templates/moderator_email_subject.html'
        users = topic.forum.moderators.all()
    else:
        subject_template = 'pybb/mail_templates/subscription_email_subject.html'
        users = topic.subscribers.exclude(pk=post.user.pk)
    subject = render_to_string(template_name=subject_template,
                                   context={'site_url': context_vars['site_url'],
                                    'post': post,
                                    'topic': topic})
    # Email subject *must not* contain newlines
    subject = ''.join(subject.splitlines())
    for user in users:
        if Email.is_blocked(user.email):
            continue
        message = get_email_message(user, **context_vars)
        if message:
            message = add_tendenci_footer(message, content_type="text")
            mails += ((subject, message, from_email, [user.email]),)
    # Send mails
    send_mass_mail(mails, fail_silently=True)
    # Reactivate previous language
    translation.activate(old_lang)