Update to 6.2 breaks email sending.
After updating to 6.2 I got this message:
Handling "Symfony\Component\Mailer\Messenger\SendEmailMessage" failed: You must configure a "Symfony\Component\Mime\BodyRendererInterface" when a "Symfony\Bridge\Twig\Mime\NotificationEmail" instance has a text or HTML template set. (500 Internal Server Error)
Just run this on your local Symfony server and go to http://localhost:8000/
symfony/symfony#48505 fixes this issue.