I am using Auto discover service Url for a specified e-mail address.
ExchangeService Service = new ExchangeService(ExchangeVersion.Exchange2010);
Service.Cr
I will recommend to you to enable Traces,to achieve this follow :
Service.TraceEnabled = true;
I was facing the same issue then when I enabled traces these traces will guide you what exactly is happening.In my case SSL certificate issue is there to solve it i followed following post
There can be many issue such as:
autodiscover.domain.com.