Fatal error: Uncaught Error: Class "Symfony\Component\Mime\Header\UnstructuredHeader" not found in /home/flighto/.drivee/vendor/symfony/postmark-mailer/Transport/MessageStreamHeader.php:16 Stack trace: #0 {main} thrown in /home/flighto/.drivee/vendor/symfony/postmark-mailer/Transport/MessageStreamHeader.php on line 16