I'm a newbie to C# development
I'm trying to migrate the EWS authentication from basic authentication to OAuth2 authentication.
#Implementation
using System;
using System.Net;
using System.Threading.Tasks;
using Microsoft.Exchange.WebServices.Data;
using Microsoft.Identity.Client;
namespace DataLoadLibrary.Email
{
public class OAuthTokenProviders
{
public static async Task<OAuthTokenProviders> Create()
{
var myClass = new OAuthTokenProviders();
await myClass.Initialize();
return myClass;
}
private OAuthTokenProviders()
{
Console.WriteLine("TESTING INSIDE CONSTRUCT");
}
private async System.Threading.Tasks.Task Initialize()
{
Console.WriteLine("TESTING");
// Using Microsoft.Identity.Client
var cca = ConfidentialClientApplicationBuilder
.Create("") //client Id
.WithClientSecret("")
.WithTenantId("")
.Build();
var ewsScopes = new string[] { "https://outlook.office365.com/.default" };
try
{
// Get token
var authResult = await cca.AcquireTokenForClient(ewsScopes)
.ExecuteAsync();
// Configure the ExchangeService with the access token
var ewsClient = new ExchangeService(ExchangeVersion.Exchange2013_SP1);
ewsClient.Url = new Uri("https://outlook.office365.com/EWS/Exchange.asmx");
ewsClient.Credentials = new OAuthCredentials(authResult.AccessToken);
ewsClient.ImpersonatedUserId =
new ImpersonatedUserId(ConnectingIdType.SmtpAddress, "");
//Include x-anchormailbox header
ewsClient.HttpHeaders.Add("X-AnchorMailbox", "");
// Make an EWS call to list folders on exhange online
var folders = ewsClient.FindFolders(WellKnownFolderName.MsgFolderRoot, new FolderView(10));
foreach (var folder in folders)
{
Console.WriteLine($"Folder: {folder.DisplayName}");
}
// Make an EWS call to read 50 emails (last 5 days) from Inbox folder
TimeSpan ts = new TimeSpan(-60, 0, 0, 0);
DateTime date = DateTime.Now.Add(ts);
SearchFilter.IsGreaterThanOrEqualTo filter = new SearchFilter.IsGreaterThanOrEqualTo(ItemSchema.DateTimeReceived, date);
var findResults = ewsClient.FindItems(WellKnownFolderName.Inbox, filter, new ItemView(50));
foreach (var mailItem in findResults)
{
Console.WriteLine($"Subject: {mailItem.Subject}");
}
EmailMessage email = new EmailMessage(ewsClient);
email.ToRecipients.Add("");
email.Subject = "HelloWorld";
email.Body = new MessageBody("This is a test email using MS Exchg we services");
email.Send();
}
catch (MsalException ex)
{
Console.WriteLine($"Error acquiring access token: {ex}");
}
catch (Exception ex)
{
Console.WriteLine($"Error: {ex}");
}
if (System.Diagnostics.Debugger.IsAttached)
{
Console.WriteLine("Hit any key to exit...");
Console.ReadKey();
}
}
}
}
Using the above implementation am able to get the access token successfully. However when am listing the folder in the mailbox, getting below exceptions
Microsoft.Exchange.WebServices.Data.ServiceRequestException
HResult=0x80131500
Message=The request failed. The underlying connection was closed: An unexpected error occurred on a send.
Source=Microsoft.Exchange.WebServices
StackTrace:
at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.GetEwsHttpWebResponse(IEwsHttpWebRequest request)
at Microsoft.Exchange.WebServices.Data.ServiceRequestBase.ValidateAndEmitRequest(IEwsHttpWebRequest& request)
at Microsoft.Exchange.WebServices.Data.MultiResponseServiceRequest`1.Execute()
at Microsoft.Exchange.WebServices.Data.ExchangeService.InternalFindFolders(IEnumerable`1 parentFolderIds, SearchFilter searchFilter, FolderView view, ServiceErrorHandling errorHandlingMode)
at Microsoft.Exchange.WebServices.Data.ExchangeService.FindFolders(FolderId parentFolderId, FolderView view)
at Microsoft.Exchange.WebServices.Data.ExchangeService.FindFolders(WellKnownFolderName parentFolderName, FolderView view)
at DataLoadLibrary.Email.OAuthTokenProviders.<Initialize>d__2.MoveNext() in C:\Users\path\to\file\DataLoadLibrary\Email\OAuthTokenProviders.cs:line 51
This exception was originally thrown at this call stack:
[External Code]
Inner Exception 1:
WebException: The underlying connection was closed: An unexpected error occurred on a send.
Inner Exception 2:
IOException: Authentication failed because the remote party has closed the transport stream.
I would want to know how to solve the exception. Thanks in Advance