AutodiscoverUrl works for all mailboxes except one

Question

This is driving me bonkers. I have been using the following c# code to pull messages from an on-prem Exchange mailbox, using Exchange Web Services:

            es = new ExchangeService(ExchangeVersion.Exchange2013_SP1)
            {
                Credentials = new WebCredentials(ConfigurationManager.AppSettings["User"].ToString(),
                                                 ConfigurationManager.AppSettings["Password"].ToString(),
                                                 ConfigurationManager.AppSettings["Domain"].ToString())
            };
            //es.TraceEnabled = true;
            es.AutodiscoverUrl(ConfigurationManager.AppSettings["MailBox"].ToString(), (a) => { return true; });

It's working fine for four previous accounts. For the most recent account that I asked to be created, I get the dreaded error:

The Autodiscover service couldn't be located.

Our Exchange folks have sworn up and down that there is no difference between the new account and the others. But there must be something different, right? Does anyone know what it could be?

I activated the trace line above to get output in the console window (code is in a console app). While I could post the entire trace for the failing account, here are the response headers for the working accounts plus the non-working account. (Server names changed.)

Good accounts

    <Trace Tag="AutodiscoverResponseHttpHeaders" Tid="1" Time="2018-01-29 21:24:45Z">
    HTTP/1.1 200 OK
    request-id: d291efce-7958-4faa-abbb-35c020f2780e
    X-CalculatedBETarget: abc123.xrdom.xrcompany.firm
    X-DiagInfo: abc123
    X-BEServer: abc123
    Persistent-Auth: true
    X-FEServer: server02
    Vary: Accept-Encoding
    Transfer-Encoding: chunked
    Cache-Control: private
    Content-Type: text/xml; charset=utf-8
    Date: Mon, 29 Jan 2018 21:24:44 GMT
    Set-Cookie: X-BackEndCookie=S-1-5-21-3649160047-1147056544-736230609-28825=u56Lnp2ejJqBm52cnsbJzJrSns3LxtLLns3G0saax5vSzM/LxpvHm8fJypqZgYHNz87H0s/N0s3Hq83Oxc3LxcvK; expires=Wed, 28-Feb-2018 21:24:45 GMT; path=/autodiscover; secure; HttpOnly
    Server: Microsoft-IIS/8.5
    X-AspNet-Version: 4.0.30319
    X-Powered-By: ASP.NET
    </Trace>

Bad Account:

    <Trace Tag="AutodiscoverResponseHttpHeaders" Tid="1" Time="2018-01-29 21:21:49Z">
    HTTP/1.1 401 Unauthorized
    request-id: 99dfa551-c4c2-441b-a317-4f4fcba21a62
    Server: Microsoft-IIS/8.5
    WWW-Authenticate: Negotiate,NTLM,Basic realm="mail.xrcompany.com"
    X-Powered-By: ASP.NET
    X-FEServer: server01
    Date: Mon, 29 Jan 2018 21:21:48 GMT
    Content-Length: 0
    </Trace>

What jumps out at me, besides the OK vs Unauthorized codes, is the different value for X-REServer.

Any help would be appreciated.

Did you perform some research on "[The Autodiscover service couldn't be located](https://stackoverflow.com/questions/15065363/autodiscover-service-couldnt-be-located-when-trying-to-access-exchange-2010-a)" ? — Jeroen Heier, Feb 12 '18 at 21:11
Yes, and none of those solutions helped. Most said that the problem were password related, but that wasn't the problem here. Other solutions, that I don't recall, also didn't apply. — BarnumBailey, Feb 12 '18 at 21:18

score 0 · Accepted Answer · answered Jun 11 '18 at 20:30

Totally forgot to close this when I discovered the problem and solution.

When the new account was created, it was not named properly. When I asked to have the name changed, only the display name was changed and not the login. Once the principal name was also corrected them everything worked.

AutodiscoverUrl works for all mailboxes except one

1 Answers1