public function copyMessage($id, $folder)
    {
        if ($this->_quota && $this->checkQuota()) {
            /**
             * @see Zend_Mail_Storage_Exception
             */
            // require_once 'Zend/Mail/Storage/Exception.php';
            throw new Zend_Mail_Storage_Exception('storage is over quota!');
        }

        if (!($folder instanceof Zend_Mail_Storage_Folder)) {
            $folder = $this->getFolders($folder);
        }

        $filedata = $this->_getFileData($id);
        $old_file = $filedata['filename'];
        $flags = $filedata['flags'];

        // copied message can't be recent
        while (($key = array_search(Zend_Mail_Storage::FLAG_RECENT, $flags)) !== false) {
            unset($flags[$key]);
        }
        $info = $this->_getInfoString($flags);

        // we're creating the copy as temp file before moving to cur/
        $temp_file = $this->_createTmpFile($folder->getGlobalName());
        // we don't write directly to the file
        fclose($temp_file['handle']);

        // we're adding the size to the filename for maildir++
        $size = filesize($old_file);
        if ($size !== false) {
            $info = ',S=' . $size . $info;
        }

        $new_file = $temp_file['dirname'] . DIRECTORY_SEPARATOR . 'cur' . DIRECTORY_SEPARATOR . $temp_file['uniq'] . $info;

        // we're throwing any exception after removing our temp file and saving it to this variable instead
        $exception = null;

        if (!copy($old_file, $temp_file['filename'])) {
            /**
             * @see Zend_Mail_Storage_Exception
             */
            // require_once 'Zend/Mail/Storage/Exception.php';
            $exception = new Zend_Mail_Storage_Exception('cannot copy message file');
        } else if (!link($temp_file['filename'], $new_file)) {
            /**
             * @see Zend_Mail_Storage_Exception
             */
            // require_once 'Zend/Mail/Storage/Exception.php';
            $exception = new Zend_Mail_Storage_Exception('cannot link message file to final dir');
        }
        @unlink($temp_file['filename']);

        if ($exception) {
            throw $exception;
        }

        if ($folder->getGlobalName() == $this->_currentFolder
            || ($this->_currentFolder == 'INBOX' && $folder->getGlobalName() == '/')) {
            $this->_files[] = array('uniq'     => $temp_file['uniq'],
                                    'flags'    => $flags,
                                    'filename' => $new_file);
        }

        if ($this->_quota) {
            $this->_addQuotaEntry((int)$size, 1);
        }
    }