Why does tlstest.paypal.com work from browser but not from my PHP code (useful for Paypal IPN)?
问题 After 2018 June 30th, Paypal won't accept non-TLS 1.2 + HTTP 1.1 requests anymore. They created the URL https://tlstest.paypal.com/ to test if connections are OK. If we open this URL in a browser, we get a successful: PayPal_Connection_OK Quesiton: why does it fail when connecting from PHP with the following code? (I get no response at all, the browser is still in waiting "state" like this, so it doesn't even arrive at echo $errno; echo $errstr; ) <?php $req = ''; // usually I use $req = 'cmd