public function zimbraPreauth(){
        $PREAUTH_KEY = env("PREAUTH_KEY");
        $domain = env("MAIL_DOMAIN");
        $backend_ip = env("BACKEND_IP");
        $id = Auth::id();
        $http = new client;
        $response = $http->request('GET',$backend_ip.'/api/account_info/'.$id, [
            'allow_redirects' => false
        ]);
        $body = json_decode($response->getBody(), true);
        $email = $body["data"]["thai_email"];
        $timestamp=(time()*1000);
        $preauthToken=hash_hmac("sha1",$email."|name|0|".$timestamp,$PREAUTH_KEY);
        $path = "/service/preauth?";
        $var = http_build_query([
            'account'     => $email,
            'expires'  => '0',
            'timestamp' => $timestamp,
            'preauth' => $preauthToken,
        ]);
        $preauthURL = "{$domain}{$path}{$var}";
        return redirect($preauthURL);
    }