Kelunik\AcmeClient\Commands\Setup::checkEmail PHP Метод

    private function checkEmail($email)
    {
        if (!is_string($email)) {
            throw new InvalidArgumentException(sprintf("\$email must be of type string, %s given.", gettype($email)));
        }
        $host = substr($email, strrpos($email, "@") + 1);
        if (!$host) {
            throw new AcmeException("Invalid contact email: '{$email}'");
        }
        try {
            (yield \Amp\Dns\query($host, Record::MX));
        } catch (NoRecordException $e) {
            throw new AcmeException("No MX record defined for '{$host}'");
        } catch (ResolutionException $e) {
            throw new AcmeException("Dns query for an MX record on '{$host}' failed for the following reason: " . $e->getMessage(), null, $e);
        }
    }