This is a minimal example to reproduce symfony/symfony #35468
# Install Dependencies
docker run --rm -i --tty \
--volume $PWD:/app \
--volume ${COMPOSER_HOME:-$HOME/.composer}:/tmp \
composer install
# Run mailer script
docker run --rm -i --tty --volume $PWD:/app php:7.3-cli php /app/send.php
Output:
Fatal error: Uncaught Symfony\Component\Mailer\Exception\HttpTransportException: Unable to send an email: The security token included in the request is invalid. (code InvalidClientTokenId). in /app/vendor/symfony/amazon-mailer/Transport/SesApiTransport.php:68