docs: def manage_mailists_on_userprofile_m2m_changed(
      action, instance, pk_set, sender, **kwargs
  ):
      """Updates the mail server mailing lists based on the
      selections in the UserProfile model.
      """
      try:
          instance.email_notifications
      except AttributeError:
          pass
      else:
          if action == "post_remove":
              update_mailing_lists_in_m2m(
                  sender=sender,
                  userprofile=instance,
                  unsubscribe=True,
                  pk_set=pk_set,
                  verbose=True,
              )
          elif action == "post_add":
              update_mailing_lists_in_m2m(
                  sender=sender,
                  userprofile=instance,
                  subscribe=True,
                  pk_set=pk_set,
                  verbose=True,
              )