Question

I’m getting an error when I attempt to connect to Exchange Web Services via ASP.NET.

The following code works if I call it via a console application but the very same code fails when executed on a ASP.NET web forms page. Just as a side note, I am using my own credentials throughout this entire code sample.

“When making a request as an account that does not have a mailbox, you must specify the mailbox primary SMTP address for any distinguished folder Ids.”

I thought I might be able to fix the issue by specifying an impersonated user.

exchangeservice.ImpersonatedUserId = 
    new ImpersonatedUserId(ConnectingIdType.SmtpAddress, "[e-mail]");

But then I get a different error.

“The account does not have permission to impersonate the requested user.”

The App Pool that the web application is running under is also my own account (same as the console application) so I have no idea what might be causing this issue.

I am using .NET framework 3.5.

Here is the code in full.

var exchangeservice =
                        new ExchangeService(ExchangeVersion.Exchange2010_SP1)
                        {
                            Timeout = 10000
                        };

 var credentials = new System.Net.NetworkCredential("username", "pass", "domain");


exchangeservice.AutodiscoverUrl("[e-mail]")

FolderId rootFolderId = new FolderId(WellKnownFolderName.Inbox);

var folderView = new FolderView(100)
            {
                Traversal = FolderTraversal.Shallow
            };

            FindFoldersResults findFoldersResults =
                service.FindFolders(rootFolderId, folderView);

Answer 1

have you tried setting the credential against the service directly?

this.exchangeService.Credentials = new WebCredentials("username", "pass");

this.exchangeService.AutodiscoverUrl("username", this.RedirectionUrlValidationCallback);

and using this as the validation callback..

    /// <summary>
    /// Redirections the URL validation callback.
    /// </summary>
    /// <param name="redirectionUrl">The redirection URL.</param>
    /// <returns>true if https</returns>
    private bool RedirectionUrlValidationCallback(string redirectionUrl)
    {
        // The default for the validation callback is to reject the URL.
        var result = false;

        var redirectionUri = new Uri(redirectionUrl);

        // Validate the contents of the redirection URL. In this simple validation
        // callback, the redirection URL is considered valid if it is using HTTPS
        // to encrypt the authentication credentials. 
        if (redirectionUri.Scheme == "https")
        {
            result = true;
        }

        return result;
    }