c# - Sharepoint 2013 EWS 受信トレイ Web パーツ エラー 401 無許可

Question

EWS を使用して受信メールにアクセスしようとしています。Kerberos が構成されました。しかし、webpart で service.UseDefaultCredentials = true を使用すると、401 エラー (未承認) が発生します。この問題を解決するための解決策は何ですか。

   private static bool ValidateCertificate(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors policyErrors) {
        return true;
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {             

            ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010_SP2);

            ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(ValidateCertificate);

            service.UseDefaultCredentials = true;

            service.Url = new Uri(EWSuri.uri);


            SearchFilter sf = new SearchFilter.SearchFilterCollection(LogicalOperator.And,
                                                                      new SearchFilter.IsEqualTo(
                                                                       EmailMessageSchema.IsRead, false), new SearchFilter.IsGreaterThan(ItemSchema.DateTimeReceived, DateTime.Now.AddDays(-14)));

            FindItemsResults<Item> findResults = service.FindItems(
                WellKnownFolderName.Inbox, sf,
                new ItemView(int.MaxValue));

            emailblock.InnerHtml = "<div data-itemscount=\"" + findResults.Items.Count + "\"></div>";

            foreach (Item item in findResults.Items)
            {
                EmailMessage mes = (EmailMessage)item;

                emailblock.InnerHtml += "<div class=\"emailitem\"><p class=\"emailline clearfix\"><span class=\"emailfield\">From:</span>" +
                            "<span class=\"emailtext\">" + " " + mes.Sender.Name + "</span></p>" +
                            "<p class=\"emailline clearfix\"><span class=\"emailfield\">Subject:</span>" +
                            "<span class=\"emailtext\">" + " " + item.Subject + "</span></p>" +
                            "<p class=\"emailline clearfix\"><span class=\"emailfield\">Received:</span>" +
                            "<span class=\"emailtext\">" + " " + item.DateTimeSent + "</span></p></div>";

            }
        }

        catch (Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverRemoteException ex)
        {
            Console.WriteLine("Exception thrown:{0}" ,ex.Message);
        }

    }