Add attachments with Craft Commerce Suppose I have an assets field in my orders fields, how could I attach those files in the confirmation email?
I suppose you could use the \craft\commerce\services\Emails::EVENT_BEFORE_SEND_MAIL event for that.

use craft\commerce\events\MailEvent;
use craft\commerce\services\Emails;
use yii\base\Event;

Event::on(
    Emails::class,
    Emails::EVENT_BEFORE_SEND_MAIL,
    function (MailEvent $e) {
        // You would be able to access the `\craft\mail\Message` like so
        // $e-&gt;craftEmail;

        // And the `\craft\commerce\elements\Order` like so
        // $e-&gt;order

        // So adding an asset could be done by accessing the `attach` method.
        // https://www.yiiframework.com/extension/yiisoft/yii2-swiftmailer/doc/api/2.1/yii-swiftmailer-message#attach()-detail
        $e-&gt;craftEmail-&gt;attach(...);
    }
);