Similar to `send_mass_template_mail` this function renders the given templates
    into email subjects and bodies.

    The emails are send one-by-one.

def send_mass_user_template_mail(subject_template, body_template, users, context):
    """
    Similar to `send_mass_template_mail` this function renders the given templates
    into email subjects and bodies.

    The emails are send one-by-one.
    """
    message_tuples = []
    for user in users:
        context['user'] = user
        subject, body = render_mail_template(subject_template, body_template, context)

        message_tuples.append((subject, body, conf.get('DEFAULT_FROM_EMAIL'), [user.email]))

    if message_tuples:
        send_mass_mail(message_tuples)