SwiftMailer not sending mail in MessageHandler

Question

I am using SwiftMailer in my Symfony 5 project to send emails.

I was using it in a controller to send a reset password e-mail, and everything was working. I am now trying to use it in a MessageHandler, here is the code I am now using :

final class SendEmailMessageHandler implements MessageHandlerInterface
{
private $mailer;

public function __construct(\Swift_Mailer $mailer)
{
    $this->mailer = $mailer;
}

public function __invoke(SendEmailMessage $message)
{
    $mail = (new \Swift_Message())
        ->setFrom($message->getFrom())
        ->setTo($message->getTo())
        ->setBody($message->getBody(), $message->getContentType())
        ->setSubject($message->getSubject());
    $response = $this->mailer->send($mail);
}
}

The response is ok, but the mail never reach my mailbox.

Here is how I am dispatching my SendEmailMessage :

class AskResetPassword extends AbstractController
{
use ResetPasswordControllerTrait;

private $resetPasswordHelper;
private $validator;
private $bus;

public function __construct(ResetPasswordHelperInterface $resetPasswordHelper, ValidatorInterface $validator, MessageBusInterface $bus)
{
    $this->resetPasswordHelper = $resetPasswordHelper;
    $this->validator = $validator;
    $this->bus = $bus;
}

public function __invoke($data)
{
    $emailConstraints = new Assert\Email();

    $email = $data->getEmail();
    if ($email) {
        $errors = $this->validator->validate($email, $emailConstraints);
        if (count($errors) === 0) {
            return $this->processPasswordReset($email);
        } else {
            return new JsonResponse(['success' => false, 'error' => 'Invalid E-Mail format'], 404);
        }
    }
}

private function processPasswordReset($email)
{
    $user = $this->getDoctrine()->getRepository(User::class)->findOneBy([
        'email' => $email,
    ]);

    $this->setCanCheckEmailInSession();

    if (!$user) {
        // Do not reveal whether a user account was found or not.
        return new JsonResponse(['success' => true], 200);
    }

    try {
        $resetToken = $this->resetPasswordHelper->generateResetToken($user);
    } catch (ResetPasswordExceptionInterface $e) {
        return new JsonResponse(['success' => false, 'error' => 'There was a problem handling your password reset request - ' . $e->getReason()]);
    }
    $message = new SendEmailMessage($email);
    $message->setFrom('from.from@from.from');
    $message->setBody(
        $this->renderView('reset_password/email.html.twig', [
            'resetToken' => $resetToken,
            'tokenLifetime' => $this->resetPasswordHelper->getTokenLifetime()
        ])
    );
    $message->setSubject('Votre demande de changement de mot de passe');
    $this->bus->dispatch($message);

    return new JsonResponse(['success' => true], 200);
}
}

Here is my swiftmailer.yaml :

swiftmailer:
    url: '%env(MAILER_URL)%'
    spool: { type: 'memory' }

Can you help me ?

Answer 1

The answer is "DO NOT spool emails unless you want to process them later". Check docs Spool Emails

A spooler is a queue mechanism which will process your message queue one by one. This was introduced when swift-mailer was rewritten and added back to symfony. In combination with Messenger Component which provides abstract interface MessageBusInterface, it would delegate to right backend service which can be smtp relay, push notification or any other type of RPC which may trigger actions on separate web services.

As symfony adds new capabilities to the message bus, this feature was added to utilize it for message queues & other services where transactional emails and notifications are processed separately.

To process your spool simply run :

APP_ENV=prod php bin/console swiftmailer:spool:send

In typical installation spooling is disabled, when you enable spooling in memory, it will wait till request is finished and kernel is about to exit. If you are using anything else to debug that terminates kernel halfway or there are other components & parts of application that keeps kernel in memory, events will not be triggered and mail will not be sent.

You can check whole documentation here : Sending Emails