Add Symfony Mailer config for Mailhog in Drupal 9 settings #2706

[luenemam]

The Problem/Issue/Bug:

How this PR Solves The Problem:

Manual Testing Instructions:

mkdir my-drupal9-site
cd my-drupal9-site
ddev config --project-type=drupal9 --docroot=web --create-docroot
ddev start
ddev composer create "drupal/recommended-project" --no-install
ddev composer require drush/drush --no-install
ddev composer require drupal/symfony_mailer --no-install
ddev composer install
ddev drush site:install -y
ddev drush pm:install symfony_mailer
ddev drush user:login "admin/config/system/mailer/test"

Use the login link to go to the page send a test mail. Verify mailhog recieves the test mail.

Automated Testing Overview:

Related Issue Link(s):

#2706

Release/Deployment notes:

[github-actions[bot]]

Download the artifacts for this pull request:

• all-ddev-executables.zip
• ddev-linux-amd64.zip
• ddev-linux-arm64.zip
• ddev-macos-amd64.zip
• ddev-macos-arm64.zip
• ddev-windows-amd64-installer.zip

[rfay]

Let me know when you've manually tested and like it, and set it to be ready for review. Thanks for this!

[rfay]

A minor update to the docs could be added to this, with a link to symfony mailer

[rfay]

This might make it into next point release if it happens this week :)

[rfay]

Rebased to pick up docs changes and a number of other things. Make sure you update your local appropriately.

[luenemam]

I've tested on GitPod. It's working as expected.

[rfay]

Thanks, I think adding the drupal10 config pre-emptively causes no harm and leaves out a whole future maintenance step.

[rfay]

Testing. Can't believe symfony mailer is alpha.

[luenemam]

Yes, they are ambitious to design a new mail system for drupal.