public static function mailListTagger(array $list)
    {
        $str = '';
        foreach ($list as $name=>$mail) {
            if (is_string($mail)) {
                $str .= self::mailTagger($mail, $name).Mailer::$ADDERSSES_SEPARATOR;
            } elseif (is_array($mail)) {
                foreach ($mail as $subname=>$submail) {
                    $str .= self::mailTagger($submail, $subname).Mailer::$ADDERSSES_SEPARATOR;
                }
            }
        }
        return $str;
    }