function Splitt(Text, Delimiter: string; Index: Integer): string;
var
  Position : Integer;
  SubIndex : Integer;
begin
  for SubIndex := 1 to Index do
    begin
      Position := Pos(Delimiter, Text);
        if Position <> 0 then
           Delete(Text, 1, Position + Length(Delimiter) - 1);
    end;
  Position := Pos(Delimiter, Text);
    if Position <> 0 then
       Text:= Copy(Text, 1, Position - 1);
  SetLength(Result, Length(Text));
  Result:= Text;
end;

procedure TForm1.Button8Click(Sender: TObject);
var
  Params           : TStringList;
  SSLIOHandler     : TIdSSLIOHandlerSocketOpenSSL;
  IdCookieManager1 : TIdCookieManager;
  SessionID        : string;
  Index            : Integer;
begin
  IdCookieManager1        := TIdCookieManager.Create(Self);
  SSLIOHandler            := TIdSSLIOHandlerSocketOpenSSL.Create;
  IdHttp1.IOHandler       := SSLIOHandler;
  IdHTTP1.CookieManager   := IdCookieManager1;
  IdHTTP1.AllowCookies    := True;
  IdHTTP1.HandleRedirects := True;

     IdHTTP1.ProtocolVersion := pv1_1; // Set HTTP Protocol Version To v1.1 (Default Value)
//     IdHTTP1.HTTPOptions:= IdHTTP1.HTTPOptions + [TIdHTTPOption.hoKeepOrigProtocol]; // Very important, otherwise Indy sets the HTTP Protocol to v1.0
     IdHTTP1.HTTPOptions := [hoKeepOrigProtocol];
     // You need a vaild User-Agent, otherwise you get wrong Cookies
     IdHTTP1.Request.UserAgent:= 'Mozilla/5.0 (Linux; U; Android 2.2.1; en-us; Nexus One Build/FRG83) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1';

     // Set all parameters
     Params := TStringList.Create;
     Params.Append('service=' + 'freemail');
     Params.Append('successURL=' + 'https://navigator.gmx.net/login');
     Params.Append('loginErrorURL=' + 'https://navigator.gmx.net/loginerror');
     Params.Append('loginFailedURL=' + 'http://www.gmx.net/logoutlounge/free_ssl/?status=login-failed&site=gmx&agof=97_L&pg=null&pa=-1&pp=___NULL&region=de');
     Params.Append('statistics=' + '');
     Params.Append('username=' + 'Beurnd_Scmhroetesr@gmx.de');
     Params.Append('password=' + '3Xra5CiYU');
     Params.Append('uinguserid=' + '');

     try
       IdHTTP1.Get('http://www.gmx.net/'); // Get vaild Cookies

       IdHTTP1.Request.ContentType   := 'application/x-www-form-urlencoded';
       IdHTTP1.Request.ContentLength := Length(Trim(Params.Text));

       IdHTTP1.Post('https://service.gmx.net/de/cgi/login?hal=true', Params);

       if IdHTTP1.Response.ResponseCode = 200 then
         begin
           Memo1.Lines.Add('Login OK');
           Memo1.Lines.Add(IdHTTP1.Response.ResponseText);
         end
       else
       if IdHTTP1.ResponseCode = 401 then
         begin
           Memo1.Lines.Add('login invalid');
         end
       else
         ShowMessage('Error')
     finally
       Params.Free;
     end;

IdHTTP1.Get('https://service.gmx.net');

        with IdCookieManager1.CookieCollection do
          for Index := 0 to Count - 1 do // alle Cookies durchsuchen

            if Cookies[Index].CookieText <> '' then
              begin
                Memo1.Lines.Add(Cookies[Index].CookieText + ' : ' + Cookies[Index].Value);
              end;


        with IdCookieManager1.CookieCollection do
          for Index := 0 to Count - 1 do // alle Cookies durchsuchen
            if Pos('JSESSIONID',Cookies[Index].CookieText) > 0 then
              begin
                SessionID := Cookies[Index].Value;
//                SessionID := Splitt(SessionID, '.', 0);
                Memo1.Lines.Add(SessionID);
              end;

// HttpFox
// https://3c.gmx.net/mail/client/settings/mailsecurity;jsessionid=19C178A2CBC5CC1222B9A96366AE379E-n4.bs62b?2-1.IBehaviorListener.0-splitPanel-splitPanel_body-childContainer-form-spamProtectionChapter-spamProtectionChapter_body-spamProtection-fieldSet-checkboxFormItem-checkboxFormItem_body-checkbox-checkbox&_=1456056625848
// Hier ist der Unterschied   -n4.bs62b?2-1

Memo1.Lines.Add(IdHTTP1.Get('https://3c.gmx.net/mail/client/settings/mailsecurity;jsessionid=' + SessionID + '.IBehaviorListener.' +
'0-splitPanel-splitPanel_body-childContainer-form-spamProtectionChapter-spamProtectionChapter_body-spamProtection-fieldSet-checkboxFormItem-checkboxFormItem_body-checkbox-checkbox&&origReferre'));

//GET /mail/client/settings/mailsecurity;jsessionid=B77C9676AB8B8202EB9BB3C6DE492FF5-n1.bs29b?10-1.IBehaviorListener.0-splitPanel-splitPanel_body-childContainer-form-spamProtectionChapter-spamProtectionChapter_body-spamProtection-fieldSet-checkboxFormItem-checkboxFormItem_body-checkbox-checkbox&_=1456045911329
//GET /mail/client/settings/mailsecurity;jsessionid=B77C9676AB8B8202EB9BB3C6DE492FF5-n1.bs29b?6-1.IBehaviorListener.0-splitPanel-splitPanel_body-childContainer-form-spamProtectionChapter-spamProtectionChapter_body-spamProtection-fieldSet-checkboxFormItem-checkboxFormItem_body-checkbox-checkbox&_=1456042796674

end;