public function setConfig(array $config) {
        $default_account = config('imap.default');
        $default_config  = config("imap.accounts.$default_account");

        foreach ($this->valid_config_keys as $key) {
            $this->$key = isset($config[$key]) ? $config[$key] : $default_config[$key];
        }

        return $this;
    }