EWS：找不到自动发现服务

Question

  

错误：找不到自动发现服务

var timeZones = TimeZoneInfo.GetSystemTimeZones();
var localTimeZone = TimeZoneInfo.Local;

var timeZone = timeZones.FirstOrDefault(x => x.StandardName == localTimeZone.StandardName) ?? localTimeZone;

var service = new ExchangeService(ExchangeVersion.Exchange2007_SP1, timeZone)
            {
                UseDefaultCredentials = true,
                Timeout = int.MaxValue
            };

service.AutodiscoverUrl(emailAddress, url => true); //Error at this line - The Autodiscover service couldn't be located.