function test_socks (proxyadr : string) : boolean;
var
  http : tidhttp;
  coo : tidcookiemanager;
  ssl : tidssliohandlersocketopenssl;
  compressor : tidcompressorzlib;
  sock : tidsocksinfo;
begin
  result := false;
  coo := tidcookiemanager.create;
  ssl := tidssliohandlersocketopenssl.create; ssl.ssloptions.method := sslvtlsv1; ssl.port := 443;
  http := tidhttp.create; http.iohandler := ssl; http.readtimeout := 60000; http.connecttimeout := 60000; http.allowcookies := true; http.handleredirects := false; http.cookiemanager := coo; http.request.useragent := 'mozilla/4.0 (compatible; msie 7.0; windows nt 6.0)'; http.request.acceptencoding := 'gzip, deflate';
  sock := tidsocksinfo.create; sock.authentication := sanoauthentication; sock.version := svsocks5; sock.host := copy (proxyadr, 1, pos (':', proxyadr) - 1); sock.port := strtoint (copy (proxyadr, pos (':', proxyadr) + 1, 5)); ssl.transparentproxy := sock;
  compressor := tidcompressorzlib.create; http.compressor := compressor;
  try
    if pos ('О компании', http.get ('https://passport.yandex.ru/passport?mode=passport'))  0 then result := true;
  except end;
  http.free; coo.free; compressor.free; ssl.free; sock.free;
end;