public function unsubscribe($token) {

        // Does the token exist in the list_unsubscribe_token database table?
        if (!$this->model->isTokenValid($token)) {
            return view('lasallecrmlistmanagement::subscribe-unsubscribe-list.token_invalid', [
                'title'    => 'Invalid Unsubscribe Token',
            ]);
        }

        $emailID  = $this->model->getEmailIdByToken($token);
        $listID   = $this->model->getListIdByToken($token);

        // email address
        $email    = $this->emailRepository->getEmailByEmailId($emailID);

        // list's name
        $listName = $this->listRepository->getListnameByListId($listID);

        // Delete all list_unsubscribe_token records for this email_id and list_id
        $this->model->deleteAllTokensForListIDandEmailID($listID,$emailID);

        // un-enabled (ie, disable) the list_email database record for this email_id and list_id
        $this->list_EmailRepository->enabledFalse($emailID, $listID);

        return view('lasallecrmlistmanagement::subscribe-unsubscribe-list.unsubscribe_success', [
            'title'    => 'Unsubscribe Successful',
            'email'    => $email,
            'listName' => $listName
        ]);
    }