Access Exchange Service From SharePoint 2013 Custom Web part getting The request failed with HTTP status 401: Unauthorized.

Question

I want to Fill a drop down with Outlook Meeting of Current log-in user in SharePoint 2013 web part for default credentials I am using the following code
 ExchangeServiceBinding binding = new ExchangeServiceBinding();
            ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => true;
            binding.RequestServerVersionValue = new RequestServerVersion();
            binding.RequestServerVersionValue.Version = ExchangeVersionType.Exchange2010_SP2;
            binding.PreAuthenticate = true;
            binding.UseDefaultCredentials = true;
            binding.Credentials = CredentialCache.DefaultCredentials ; 
            string server = "https://*********/ews/Exchange.asmx";
            binding.Url = server;
I Am Getting the Error "The request failed with HTTP status 401: Unauthorized."
but when I Replace  the line  
binding.Credentials = CredentialCache.DefaultCredentials ; 
with 
 binding.Credentials = new NetworkCredential(userName, password, domain);
Its run fine.  Is there any way I could able to use default credential.
  

Answer 1

Hi,
As this question is more relate to Exchange development, I suggest you post it to the corresponding forum, you will get more help and confirmed answers from there.
http://social.msdn.microsoft.com/Forums/office/en-US/home?category=exchangeserver
Best regards
Patrick Liang
TechNet Community Support