The Autodiscover service couldn't be located in C# but works for Outlook

Question

Tried everything I've found and keep getting this error using AutodiscoverUrl call on EWS service.

have tried supplying webcredentials, networkcredentials, and none. If I set the service.Url property myself then it works. I can access EWS calls no problem.

This is the call stack when it errors.

A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.ObjectDisposedException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException'     occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.ObjectDisposedException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'Microsoft.Exchange.WebServices.Dns.DnsException' occurred in Microsoft.Exchange.WebServices.dll
A first chance exception of type 'Microsoft.Exchange.WebServices.Data.AutodiscoverLocalException' occurred in Microsoft.Exchange.WebServices.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.ObjectDisposedException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.Sockets.SocketException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.Security.Authentication.AuthenticationException' occurred in System.dll
A first chance exception of type 'System.ObjectDisposedException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'System.Net.WebException' occurred in System.dll
A first chance exception of type 'Microsoft.Exchange.WebServices.Dns.DnsException' occurred in Microsoft.Exchange.WebServices.dll
A first chance exception of type 'Microsoft.Exchange.WebServices.Data.AutodiscoverLocalException' occurred in Microsoft.Exchange.WebServices.dll


An unhandled exception of type 'Microsoft.Exchange.WebServices.Data.AutodiscoverLocalException' occurred in Microsoft.Exchange.WebServices.dll

Additional information: The Autodiscover service couldn't be located.

I have also checked I can ping the Exchange server via dns entry autodiscover. I've checked the AD for the SCP and it looks ok. Outlook can find the Autodiscover no problems. Only my code can't.

In case it matters, all of my machines are Azure vm's on a virtual subnet.

My code:

ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2013_SP1);
service.AutodiscoverUrl("Lyynx@ocean.lythixdesigns.com"); // Exception is thrown here

Answer 1

After decompiling and debugging the exceptions being thrown, I discovered that due to using a self signed certificate it was not allowing the autodiscover url to be used.

http://blogs.msdn.com/b/robert_mcmurray/archive/2013/11/15/how-to-trust-the-iis-express-self-signed-certificate.aspx

This url shows how to copy the certificate into the Trusted Root Certification Authorities folder in Internet Explorer. I ran IE as Administrator and copied it in. My code now works. It hit one more exception saying it was not authenticated but I think that's where it then uses the log in credentials.

So trusting the certificate was the answer to my issue.