Michael Stenta
--- a/core/lib/Drupal/Core/Mail/Plugin/Mail/SymfonyMailer.php
+++ b/core/lib/Drupal/Core/Mail/Plugin/Mail/SymfonyMailer.php
        ->subject($message['subject'])
        ->text($message['body']);

-      $mailer = $this->getMailer();
-      $mailer->send($email);
+      // Disable logging, it's verbose and throws exceptions
+      // on transport shutdown.
+      // @see https://www.drupal.org/project/drupal/issues/3420372
+      $this->logger = new NullLogger();
+      $this->getMailer()->send($email);
--- a/core/lib/Drupal/Core/Mail/Plugin/Mail/SymfonyMailer.php
+++ b/core/lib/Drupal/Core/Mail/Plugin/Mail/SymfonyMailer.php
      //
      // The MessageEvent will likely play an important role in an upcoming mail
      // API. However, emails handled by this plugin already were processed by
      // hook_mail and hook_mail_alter. Firing the MessageEvent would leak those
      // mails into the code path (i.e., event subscribers) of the new API.
      // Therefore, this plugin deliberately refrains from injecting the event
      // dispatcher.
      $factories = Transport::getDefaultFactories(logger: $this->logger);
-      $factories = Transport::getDefaultFactories(logger: $this->logger);
+      $factories = Transport::getDefaultFactories();