Queueing Mail

Queueing Mailer Actions

Add Cake\Queue\Mailer\QueueTrait to a mailer to make its actions queueable:

<?php
declare(strict_types=1);

namespace App\Mailer;

use Cake\Mailer\Mailer;
use Cake\Queue\Mailer\QueueTrait;

class UserMailer extends Mailer
{
    use QueueTrait;

    public function welcome(string $emailAddress, string $username): void
    {
        $this
            ->setTo($emailAddress)
            ->setSubject(sprintf('Welcome %s', $username));
    }
}

Queue an action with push():

$this->getMailer('User')->push('welcome', ['[email protected]', 'josegonzalez']);

QueueTrait::push() creates an intermediate MailerJob that executes the mailer action later. Its signature mirrors Mailer::send() and also accepts the same queueing $options supported by QueueManager::push().

If the mailer or email instance cannot be created, the action name is invalid, or the action throws BadMethodCallException, the message is rejected.

Delivering Mail Through Queue Jobs

If you do not use mailers, configure Cake\Queue\Mailer\Transport\QueueTransport as an email transport:

use Cake\Queue\Mailer\Transport\QueueTransport;

return [
    'EmailTransport' => [
        'default' => [
            'className' => MailTransport::class,
        ],
        'queue' => [
            'className' => QueueTransport::class,
            'transport' => 'default',
        ],
    ],
    'Email' => [
        'default' => [
            'transport' => 'queue',
        ],
    ],
];

With this configuration, sending mail with the default email profile creates a queue message. When that message is processed, the configured underlying transport sends the email.