'Autodiscover service couldn't be located': Exchange -

exchangeservice service = new exchangeservice(exchangeversion.exchange2007_sp1); service.credentials = new webcredentials("abc", "123456", "mydomain.net"); service.traceenabled = true; service.usedefaultcredentials = false; service.enablescplookup = false; service.autodiscoverurl("abc@mydomain.net"); folder inbox = folder.bind(service, wellknownfoldername.inbox); console.writeline("the folder name " + inbox.displayname.tostring()); 

i trying login exchange keep error of 'autodiscover service couldn't located'. username-password fine.