CHANGELOG

5.2.0

added NativeTransportFactory to configure a transport based on php.ini settings
added local_domain, restart_threshold, restart_threshold_sleep and ping_threshold options for smtp
added command option for sendmail

[BC BREAK] changed the NullTransport DSN from smtp://null to null://null
[BC BREAK] renamed SmtpEnvelope to Envelope, renamed DelayedSmtpEnvelope to DelayedEnvelope
[BC BREAK] changed the syntax for failover and roundrobin DSNs

Before:

dummy://a || dummy://b (for failover) dummy://a && dummy://b (for roundrobin)

After:

failover(dummy://a dummy://b) roundrobin(dummy://a dummy://b)

added support for multiple transports on a Mailer instance
[BC BREAK] removed the auth_mode DSN option (it is now always determined automatically)
STARTTLS cannot be enabled anymore (it is used automatically if TLS is disabled and the server supports STARTTLS)
[BC BREAK] Removed the encryption DSN option (use smtps instead)
Added support for the smtps protocol (does the same as using smtp and port 465)
Added PHPUnit constraints
Added MessageDataCollector
Added MessageEvents and MessageLoggerListener to allow collecting sent emails
[BC BREAK] TransportInterface has a new __toString() method
[BC BREAK] Classes AbstractApiTransport and AbstractHttpTransport moved under Transport sub-namespace.
[BC BREAK] Transports depend on Symfony\Contracts\EventDispatcher\EventDispatcherInterface instead of Symfony\Component\EventDispatcher\EventDispatcherInterface.
Added possibility to register custom transport for dsn by implementing Symfony\Component\Mailer\Transport\TransportFactoryInterface and tagging with mailer.transport_factory tag in DI.
Added Symfony\Component\Mailer\Test\TransportFactoryTestCase to ease testing custom transport factories.
Added SentMessage::getDebug() and TransportExceptionInterface::getDebug to help debugging
Made MessageEvent final
add DSN parameter verify_peer to disable TLS peer verification for SMTP transport