docs: 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)