AutodiscoverService autodiscoverService = new AutodiscoverService(exchangeVersion); //2010
autodiscoverService.setCredentials(exchangeCredentials);
WebProxy proxy = createWebProxy(proxyConfiguration);
            autodiscoverService.setWebProxy(proxy);

response = autodiscoverService.getUserSettings(userSmtpAddress, InterestedUserSettings);
Map<UserSettingName, Object> userSettingsMap = response.getSettings();

        if (autodiscoverService.isExternal()) {
            EWSUrl = (String) userSettingsMap
                    .get(UserSettingName.ExternalEwsUrl);
        } else {
            EWSUrl = (String) userSettingsMap
                    .get(UserSettingName.InternalEwsUrl);
        }
return EWSUrl;

--------------------

private static final UserSettingName[] InterestedUserSettings = new UserSettingName[] {
            UserSettingName.InternalEwsUrl, UserSettingName.ExternalEwsUrl,
            UserSettingName.UserDN, UserSettingName.UserDisplayName,
            UserSettingName.MailboxDN, UserSettingName.CasVersion,
            UserSettingName.InternalRpcClientServer,
            UserSettingName.InternalMailboxServerDN};


public static WebProxy createWebProxy(ProxyConfiguration proxyConfiguration) {
        if (proxyConfiguration.getCredentials() != null && !StringUtil.isEmptyOrNull(proxyConfiguration.getCredentials().getUsername())) {
            return new WebProxy(proxyConfiguration.getHostname(), proxyConfiguration.getPort(),
                    new WebProxyCredentials(proxyConfiguration.getCredentials().getUsername(),
                            proxyConfiguration.getCredentials().getPassword(), null));
        } else {
            return new WebProxy(proxyConfiguration.getHostname(), proxyConfiguration.getPort());
        }
    }

public class HttpClientWebRequest extends HttpWebRequest {
...
private HttpRequestBase httpPost = null;
...
public void prepareConnection() {
    httpPost = "GET".equals(this.getRequestMethod()) ? new HttpGet(getUrl().toString()) : new HttpPost(getUrl().toString());

public static URI autoDiscoverURI(String emailAddress, String password)
{
    URI url = null;
    ExchangeService service = new ExchangeService();
    ExchangeCredentials credentials = new WebCredentials(emailAddress, password);
    service.setCredentials(credentials);
    try
    {
        service.autodiscoverUrl(emailAddress, new IAutodiscoverRedirectionUrl()
        {
            @Override
            public boolean autodiscoverRedirectionUrlValidationCallback(String url) throws AutodiscoverLocalException
            {
                return url.startsWith("https:");
            }
        });
        url = service.getUrl();
    }
    catch (Exception e)
    {
        System.out.println(e.toString());
    }
    finally
    {
        service.close();
    }
    return url;
}

Properties systemProps = System.getProperties();
systemProps.put("javax.net.ssl.trustStore",
              "C:/Program Files/Java/jdk1.8.0/jre/lib/security/cacerts");
systemProps.put("javax.net.ssl.trustStorePassword","changeit");
System.setProperties(systemProps);
service = new ExchangeService(ExchangeVersion.Exchange2010_SP1);
ExchangeCredentials credentials = new WebCredentials("FirstnameSecondname", "myPW","EXCHANGE2010.intern.mycompany.com");
service.setCredentials(credentials);
service.setTraceEnabled(true);
service.setTraceFlags(EnumSet.allOf(TraceFlags.class)); 
service.setTraceListener(new ITraceListener() {
            public void trace(String traceType, String traceMessage) {
                System.out.println("Type:" + traceType + " Message:" + traceMessage);
            }
        });
        service.autodiscoverUrl("[email protected]", new                       IAutodiscoverRedirectionUrl() {
                public boolean autodiscoverRedirectionUrlValidationCallback(String url)
                        throws AutodiscoverLocalException {
                            System.out.println("url: " + url.toLowerCase().startsWith("https://"));
                    return url.toLowerCase().startsWith("https://");
                }
            });