// DocumentNOW V2 AsyncCloseEnvelope example  // force TLS 1.2 if .net < 4.6 ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12;  Guid accountContextID = new Guid(<fromYourAccount>); // see CreateEnvelope Guid envelopeId = new Guid(<fromCreateEnvelope>);  Guid authToken = new Guid(<fromCreateEnvelope>);  // assuming we set the namespace on the service proxy to DocNow ... DocNow.EnvelopeServiceClient client = new DocNow.EnvelopeServiceClient("BasicHttpBinding_IEnvelopeService1"); DocNow.CloseEnvelopeRequest request = new DocNow.CloseEnvelopeRequest();  request.ContextIdentifier = accountContextID; request.EnvelopeId = envelopeId request.AuthToken = authToken;  DocNow.AsyncCloseEnvelopeResult result = client.AsyncCloseEnvelope(request);  if (result.Exceptions != null) {     StringBuilder sb = new StringBuilder();     foreach (DocNow.EnvelopeException exception in result.Exceptions)     {         sb.AppendFormat("{0} : {1}{2}", exception.Severity.ToString(), exception.Value, Environment.NewLine);      }     Console.WriteLine(sb.ToString()); } else {     // the result will return back result.SessionID that can be used with the LookupSession operation to return the results that would have actually been returned has the CloseEnvelope operation been called synchronously. }