docs: def send_mass_template_mail(subject_template, body_template, recipients, context=None):
      """
      Renders an email subject and body using the given templates and context,
      then sends it to the given recipients list.
  
      The emails are send one-by-one.
      """
      if context:
          subject, body = render_mail_template(subject_template, body_template, context)
      else:
          subject, body = subject_template, body_template
  
      message_tuples = [(subject, body, conf.get('DEFAULT_FROM_EMAIL'), [r]) for r in recipients]
  
      send_mass_mail(message_tuples)