code: def send_activation_email(self, request, queryset):
          
          n = 0
          for user in queryset:
              if not user.is_active and settings.USERS_VERIFY_EMAIL:
                  send_activation_email(user=user, request=request)
                  n += 1
  
          self.message_user(
              request, _('Activation emails sent to %(count)d %(items)s.') %
              {'count': n, 'items': model_ngettext(self.opts, n)},  messages.SUCCESS)
docs: Send activation emails for the selected users, if they are not already
          activated.