public function cci()
    {
        $mails = func_get_args();

        foreach ($mails as $mail) {
            if (is_string($mail)) {
                $this->_cci[] = $mail;
            } elseif (is_array($mail)) {
                foreach ($mail as $submail) {
                    $this->_cci[] = $submail;
                }
            }
        }

        return $this;
    }