File: //usr/share/php/Symfony/Bundle/FrameworkBundle/Resources/config/mailer.xml
<?xml version="1.0" encoding="UTF-8" ?>
<container xmlns="http://symfony.com/schema/dic/services"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
<services>
<service id="mailer.mailer" class="Symfony\Component\Mailer\Mailer">
<argument type="service" id="mailer.default_transport" />
<argument type="service" id="messenger.default_bus" on-invalid="ignore" />
</service>
<service id="mailer" alias="mailer.mailer" />
<service id="Symfony\Component\Mailer\MailerInterface" alias="mailer.mailer" />
<service id="mailer.default_transport" class="Symfony\Component\Mailer\Transport\TransportInterface">
<factory class="Symfony\Component\Mailer\Transport" method="fromDsn" />
<argument /> <!-- env(MAILER_DSN) -->
<argument type="service" id="event_dispatcher" />
<argument type="service" id="http_client" on-invalid="ignore" />
<argument type="service" id="logger" on-invalid="ignore" />
</service>
<service id="Symfony\Component\Mailer\Transport\TransportInterface" alias="mailer.default_transport" />
<service id="mailer.messenger.message_handler" class="Symfony\Component\Mailer\Messenger\MessageHandler">
<argument type="service" id="mailer.default_transport" />
<tag name="messenger.message_handler" />
</service>
</services>
</container>