(EWS) How to call autodiscover URL to retrieve exchange service URL?

Question

Hi Folks,
I have some code that finds the autodiscover url by searching on the SCP.  What I would like to do is then call the auto discover service at that location to determine the URL of the ExchangeService for making EWS calls.
The examples I can find in the MS documentation use an email address (ExchangeService.AutoDiscoverURL  and GetUserSettingsResponse).
What I would like to do is call the service located at the address given by the SCP and then set the ExchangeService.Url property.
I am aware that I need to use the ASUrl property of the AutoDiscover Response (POX), however, I do not seem to be able to find any information on how to make the request (using C#) and how to retrieve the response.
Regards
Andy

Answer 1

You can use the Autodiscover classes to do an Autodiscover against your SCP endpoint (although I don't really see the point when you use AutoDiscoverURL it will do a SCP lookup first anyway?).
eg to use the Autodiscover class you can use
adAutoDiscoverService.Url = new Uri(" https://autodiscover-s.outlook.com/autodiscover/autodiscover.svc");
adAutoDiscoverService.Credentials = new NetworkCredential(UserName,Password);
adAutoDiscoverService.EnableScpLookup = false;
adAutoDiscoverService.RedirectionUrlValidationCallback = adAutoDiscoCallBack;
adAutoDiscoverService.PreAuthenticate = true;
GetUserSettingsResponse adResponse = adAutoDiscoverService.GetUserSettings(Identity, (new UserSettingName[1] { UserSettingName.ExternalEwsUrl }));
if (adResponse.Settings.Count >= 1)
String exClientURL = (String)adResponse.Settings[UserSettingName.ExternalEwsUrl];
CASURL = exClientURL;
This will do a SOAP Autodiscover rather then POX if you want to do a POX discover you can do something like
String EWSURL = null;
String auDisXML = "<Autodiscover xmlns=\"http://schemas.microsoft.com/exchange/autodiscover/outlook/requestschema/2006\"><Request>" +
"<EMailAddress>" + Identity + "</EMailAddress>" +
"<AcceptableResponseSchema>http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a</AcceptableResponseSchema>" +
"</Request>" +
"</Autodiscover>";
System.Net.HttpWebRequest adAutoDiscoRequest = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(adURL);
adAutoDiscoRequest.ContentType = "text/xml";
adAutoDiscoRequest.Headers.Add("Translate", "F");
adAutoDiscoRequest.Method = "Post";
adAutoDiscoRequest.Credentials = NetCredential;
byte[] bytes = Encoding.UTF8.GetBytes(auDisXML);
adAutoDiscoRequest.ContentLength = bytes.Length;
Stream rsRequestStream = adAutoDiscoRequest.GetRequestStream();
rsRequestStream.Write(bytes, 0, bytes.Length);
rsRequestStream.Close();
WebResponse adResponse = adAutoDiscoRequest.GetResponse();
Stream rsResponseStream = adResponse.GetResponseStream();
XmlDocument reResponseDoc = new XmlDocument();
reResponseDoc.Load(rsResponseStream);
String EWSURL = "";
XmlNodeList pfProtocolNodes = reResponseDoc.GetElementsByTagName("Protocol");
foreach (XmlNode xnNode in pfProtocolNodes)
XmlNodeList adChildNodes = xnNode.ChildNodes;
foreach (XmlNode xnSubChild in adChildNodes)
switch (xnSubChild.Name)
case "ASUrl": EWSURL = xnSubChild.InnerText;
break;
Cheers
Glen