Fatal error: Uncaught Error: Class "GuzzleHttp\Exception\TransferException" not found in /var/www/html/smtp/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php:15 Stack trace: #0 {main} thrown in /var/www/html/smtp/vendor/guzzlehttp/guzzle/src/Exception/RequestException.php on line 15