How to disable “verify_peer” with Symfony Mailer component?

Question

I\'m configuring a mail server (postfix), with a self signed certificate, and it seems this self signed certificate is a problem for the Symfony Mailer component.

On

Answer 1

Unfortunatly verify_peer feature is not in symfony 4.4 (yet) as @yivi states correctly.

I tried updating symfony/mailer in composer to dev-master but symfony flex constraints doesnt allow this due to:

Restricting packages listed in "symfony/symfony" to "4.4.*"

So i ended up overriding mailer.transport_factory.smtp:

mailer.transport_factory.smtp:
    class: App\Mailer\EsmtpTransportFactory
    tags:
      - { name: 'mailer.transport_factory', priority: "-100" }

with a custom EsmtpTransportFactory that contains this feature:

getScheme() ? true : null;
        $port = $dsn->getPort(0);
        $host = $dsn->getHost();

        $transport = new EsmtpTransport($host, $port, $tls, $this->dispatcher, $this->logger);

        if (!$dsn->getOption('verify_peer', true)) {
            /** @var SocketStream $stream */
            $stream = $transport->getStream();
            $streamOptions = $stream->getStreamOptions();

            $streamOptions['ssl']['verify_peer'] = false;
            $streamOptions['ssl']['verify_peer_name'] = false;

            $stream->setStreamOptions($streamOptions);
        }

        if ($user = $dsn->getUser()) {
            $transport->setUsername($user);
        }

        if ($password = $dsn->getPassword()) {
            $transport->setPassword($password);
        }

        return $transport;
    }

    protected function getSupportedSchemes(): array
    {
        return ['smtp', 'smtps'];
    }
}

Note the bool value if verify_peer in the DSN can't be a string.
This will not work: MAILER_DSN=smtp://foo@default?verify_peer=false
This will work: MAILER_DSN=smtp://foo@default?verify_peer=0
or as mentioned in this comment:

parameters:
  env(verify): 'false'

framework:
  mailer:
  dsn: '%env(MAILER_DSN)%?verify_peer=%env(bool:verify)%'

I guess it would be better if this feature was ported to 4.4 but so long i use this workaround.