[Mailer] Add FailedMessageEvent and SentMessageEvent

Author: mdoutreluingne

mailer.rst

@@ -1419,7 +1419,7 @@ is sent::
 
     class MailerSubscriber implements EventSubscriberInterface
     {
-        public static function getSubscribedEvents()
+        public static function getSubscribedEvents(): array
         {
             return [
                 MessageEvent::class => 'onMessage',
@@ -1437,6 +1437,65 @@ is sent::
         }
     }
 
+SentMessageEvent
+~~~~~~~~~~~~
+
+``SentMessageEvent`` it allows acting on the :class:`Symfony\\Component\\Mailer\\SentMessage`::
+
+    use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+    use Symfony\Component\Mailer\Event\SentMessageEvent;
+    use Symfony\Component\Mailer\SentMessage;
+
+    class MailerSubscriber implements EventSubscriberInterface
+    {
+        public static function getSubscribedEvents(): array
+        {
+            return [
+                SentMessageEvent::class => 'onMessage',
+            ];
+        }
+
+        public function onMessage(SentMessageEvent $event): void
+        {
+            $message = $event->getMessage();
+            if (!$message instanceof SentMessage) {
+                return;
+            }
+
+            // do something with the message
+        }
+    }
+
+FailedMessageEvent
+~~~~~~~~~~~~
+
+``FailedMessageEvent`` it allows acting on the the initial message in case of a failure::
+
+    use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+    use Symfony\Component\Mailer\Event\FailedMessageEvent;
+
+    class MailerSubscriber implements EventSubscriberInterface
+    {
+        public static function getSubscribedEvents(): array
+        {
+            return [
+                FailedMessageEvent::class => 'onMessage',
+            ];
+        }
+
+        public function onMessage(FailedMessageEvent $event): void
+        {
+            // e.g you can debug sending an email with the getError() method
+            $event->getError();
+
+            // do something with the message
+        }
+    }
+
+.. versionadded:: 6.2
+
+    ``SentMessageEvent`` and ``FailedMessageEvent`` was introduced in Symfony 6.2.
+
 Development & Debugging
 -----------------------