Merge branch '5.2' into 5.x

* 5.2:
  Complete documentation about mailer integration
  Complete documentation about mailer integration
  [#14083] Revert mailer.headers option in 4.4 - 5.1

Author: wouterj

mailer.rst

@@ -46,6 +46,7 @@ over SMTP by configuring the DSN in your ``.env`` file (the ``user``,
             xsi:schemaLocation="http://symfony.com/schema/dic/services
                 https://symfony.com/schema/dic/services/services-1.0.xsd
                 http://symfony.com/schema/dic/symfony https://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
+
             <framework:config>
                 <framework:mailer dsn="%env(MAILER_DSN)%"/>
             </framework:config>
@@ -55,6 +56,7 @@ over SMTP by configuring the DSN in your ``.env`` file (the ``user``,
 
         // config/packages/mailer.php
         use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
+
         return static function (ContainerConfigurator $containerConfigurator): void {
             $containerConfigurator->extension('framework', [
                 'mailer' => [
@@ -71,19 +73,25 @@ over SMTP by configuring the DSN in your ``.env`` file (the ``user``,
 Using Built-in Transports
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-============  ========================================  ==============================
+.. versionadded:: 5.2
+
+    The native protocol was introduced in Symfony 5.2.
+
+============  ========================================  ==============================================================
 DSN protocol  Example                                   Description
-============  ========================================  ==============================
-smtp          ``smtp://user:pass@smtp.example.com:25``  Mailer uses an SMTP server to
-                                                        send emails
-sendmail      ``sendmail://default``                    Mailer uses the local sendmail
-                                                        binary to send emails
-============  ========================================  ==============================
+============  ========================================  ==============================================================
+smtp          ``smtp://user:pass@smtp.example.com:25``  Mailer uses an SMTP server to send emails
+sendmail      ``sendmail://default``                    Mailer uses the local sendmail binary to send emails
+native        ``native://default``                      Mailer uses the sendmail binary and options configured
+                                                        in the ``sendmail_path`` setting of ``php.ini``. On Windows
+                                                        hosts, Mailer fallbacks to ``smtp`` and ``smtp_port``
+                                                        ``php.ini`` settings when ``sendmail_path`` is not configured.
+============  ========================================  ==============================================================
 
 Using a 3rd Party Transport
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Instead of using your own SMTP server, you can send emails via a 3rd party
+Instead of using your own SMTP server or sendmail binary, you can send emails via a 3rd party
 provider. Mailer supports several - install whichever you want:
 
 ==================  ==============================================

reference/configuration/framework.rst

@@ -178,6 +178,7 @@ Configuration
 
   * :ref:`dsn <mailer-dsn>`
   * `transports`_
+  * `message_bus`_
   * `envelope`_
 
     * `sender`_
@@ -3009,6 +3010,18 @@ transports
 A :ref:`list of DSN <multiple-email-transports>` that can be used by the
 mailer. A transport name is the key and the dsn is the value.
 
+message_bus
+...........
+
+.. versionadded:: 5.1
+
+    The ``message_bus`` option was introduced in Symfony 5.1.
+
+**type**: ``string`` **default**: ``null`` or default bus if Messenger component is installed
+
+Service identifier of the message bus to use when using the
+:doc:`Messenger component </messenger>` (e.g. ``messenger.default_bus``).
+
 envelope
 ........
 
@@ -3063,6 +3076,7 @@ recipients set in the code.
 
         // config/packages/mailer.php
         namespace Symfony\Component\DependencyInjection\Loader\Configurator;
+
         return static function (ContainerConfigurator $containerConfigurator): void {
             $containerConfigurator->extension('framework', [
                 'mailer' => [
@@ -3082,10 +3096,14 @@ recipients set in the code.
 headers
 .......
 
+.. versionadded:: 5.2
+
+    The ``headers`` mailer option was introduced in Symfony 5.2.
+
 **type**: ``array``
 
-Headers to add to emails. key (``name`` attribute in xml format)
-is the header name and value the header value.
+Headers to add to emails. The key (``name`` attribute in xml format) is the
+header name and value the header value.
 
 workflows
 ~~~~~~~~~