“Warning: stream_socket_enable_crypto(): this stream does not support SSL/crypto” is a message you will often come across when doing mail send work in PHP, particularly when your SMTP settings require you to connect using either a SSL or TLS mode.

The reason for the PHP warning message is actually not insidious at all – 99% of the time it refers to the fact that the OpenSSL extension hasn’t been enabled in your PHP configuration file – and under XAMPP this is almost always the case.

So a simple fix is to navigate to your php.ini file (for XAMPP it usually sits under xampp\apache\bin\php.ini), open it up and run a search for “extension=php_openssl.dll”.

Uncomment this line by removing the semi-colon at the front of it, save the file and then restart Apache via the Services panel.