protected function conn_configure($dsn, $dbh)
    {
        // Initialize database structure in file is empty
        if (!empty($dsn['database']) && !filesize($dsn['database'])) {
            $data = file_get_contents(RCUBE_INSTALL_PATH . 'SQL/sqlite.initial.sql');

            if (strlen($data)) {
                $this->debug('INITIALIZE DATABASE');

                $q = $dbh->exec($data);

                if ($q === false) {
                    $error = $dbh->errorInfo();
                    $this->db_error = true;
                    $this->db_error_msg = sprintf('[%s] %s', $error[1], $error[2]);

                    rcube::raise_error(array('code' => 500, 'type' => 'db',
                        'line' => __LINE__, 'file' => __FILE__,
                        'message' => $this->db_error_msg), true, false);
                }
            }
        }
    }