[Intermediate] Complete Guide to Asynchronous Processing in Laravel Using Mail & Job Queues

What You’ll Learn

• How to create email templates with Mailable classes
• Configuring mail drivers & queue drivers
• Implementing asynchronous mail sending via Job classes
• Managing queues with Laravel Horizon & Supervisor
• Accessibility best practices for email content

Who This Is For

• Intermediate Laravel engineers implementing email notifications
• Developers looking to speed up response times with async processing
• Project leaders seeking queue visibility and stable operations

Accessibility Level: ★★★☆☆

Covers alt text for images, plain-text fallbacks, color contrast, and language attributes.

1. Introduction: Why Use Mail + Queues?

Synchronous email notifications (user sign-up, password resets, etc.) can slow down your HTTP responses.
By combining Laravel’s job queue with mail, you can offload email sending to the background and return responses immediately.

• Speed: Return HTTP responses instantly
• Reliability: Retry on transient failures
• Scalability: Distribute load across multiple workers

2. Setup: Configuring Mail & Queue Drivers

Add these to your .env file:

# Mail driver (smtp / mailgun / ses, etc.)
MAIL_MAILER=smtp
MAIL_HOST=smtp.mailtrap.io
MAIL_PORT=2525
MAIL_USERNAME=your_username
MAIL_PASSWORD=your_password
MAIL_ENCRYPTION=tls
MAIL_FROM_ADDRESS=no-reply@example.com
MAIL_FROM_NAME="YourApp"

# Queue driver (database / redis / sqs, etc.)
QUEUE_CONNECTION=database

Run migration for the database queue:

php artisan queue:table
php artisan migrate

• QUEUE_CONNECTION=database stores jobs in the jobs table
• For Redis: set REDIS_HOST etc. in .env, then QUEUE_CONNECTION=redis

3. Building a Mailable & Template

3.1 Generate a Mailable

php artisan make:mail WelcomeMail --markdown=emails.welcome

// app/Mail/WelcomeMail.php
namespace App\Mail;

use Illuminate\Bus\Queueable;
use Illuminate\Mail\Mailable;
use Illuminate\Queue\SerializesModels;

class WelcomeMail extends Mailable
{
    use Queueable, SerializesModels;

    public $user;

    public function __construct($user)
    {
        $this->user = $user;
    }

    public function build()
    {
        return $this->subject('Welcome!')
                    ->markdown('emails.welcome');
    }
}

3.2 Edit the Markdown View

{{-- resources/views/emails/welcome.blade.php --}}
@component('mail::message')
# Hello, {{ $user->name }}

Thank you for registering! Please click the button below to set up your profile.

@component('mail::button', ['url' => url('/profile')])
Set Up Profile
@endcomponent

Thanks,<br>
{{ config('app.name') }}
@endcomponent

• @component('mail::message') generates a responsive layout
• Add ->text('emails.welcome_plain') for a plain-text version, and include alt attributes on any images

4. Asynchronous Dispatch with a Job

4.1 Create a Job Class

php artisan make:job SendWelcomeEmail

// app/Jobs/SendWelcomeEmail.php
namespace App\Jobs;

use App\Mail\WelcomeMail;
use Illuminate\Bus\Queueable;
use Illuminate\Support\Facades\Mail;
use Illuminate\Queue\SerializesModels;
use Illuminate\Contracts\Queue\ShouldQueue;

class SendWelcomeEmail implements ShouldQueue
{
    use Queueable, SerializesModels;

    protected $user;

    public function __construct($user)
    {
        $this->user = $user;
    }

    public function handle()
    {
        Mail::to($this->user->email)
            ->send(new WelcomeMail($this->user));
    }
}

4.2 Dispatch the Job in Your Controller

// app/Http/Controllers/Auth/RegisterController.php
use App\Jobs\SendWelcomeEmail;

protected function registered(Request $request, $user)
{
    // Dispatch the job instead of sending synchronously
    SendWelcomeEmail::dispatch($user)->delay(now()->addSeconds(10));
}

• Implementing ShouldQueue auto-pushes the job to the queue
• Use delay() to postpone execution

5. Queue Management: Horizon & Supervisor

5.1 Monitor with Laravel Horizon

composer require laravel/horizon
php artisan horizon:install
php artisan migrate

• Provides a dashboard for job status & performance
• Works with Redis queue driver only

5.2 Run Workers with Supervisor

# /etc/supervisor/conf.d/laravel-worker.conf
[program:laravel-worker]
process_name=%(program_name)s_%(process_num)02d
command=php /path/to/artisan queue:work redis --sleep=3 --tries=3
autostart=true
autorestart=true
numprocs=2
user=www-data
redirect_stderr=true
stdout_logfile=/var/log/laravel-worker.log

supervisorctl reread
supervisorctl update
supervisorctl start laravel-worker:*

• Auto-restart and multiple processes ensure high availability

6. Email Accessibility Best Practices

• Alt Text: Always include alt attributes on images/buttons
• Plain-Text Version: Bundle a fallback plain-text view for screen readers
• Language Attribute: Add <html lang="ja"> (or appropriate lang) in your email templates
• Color Contrast: Ensure button/background text meets WCAG 2.1 AA contrast ratios

7. Summary & Checklist

1. Configure mail & queue drivers in .env
2. Design email layouts using Mailable classes & Markdown templates
3. Offload mail sending to queues with a ShouldQueue Job
4. Monitor with Horizon and run workers under Supervisor
5. Verify alt text, plain-text fallback, language tags, and contrast ratios

You now have a fast, reliable, and accessible email notification foundation. Implement it in your project and delight your users! ♡