Send email with Laravel

<?php
namespace App\Mail;

use App\Models\Order;
use Illuminate\Mail\Attachment;
use Illuminate\Mail\Mailable;
use Illuminate\Mail\Mailables\Address;
use Illuminate\Mail\Mailables\Content;
use Illuminate\Mail\Mailables\Envelope;
use Illuminate\Mail\Mailables\Headers;

class OrderReceipt extends Mailable
{
    public function __construct(public Order $order) {}

    public function envelope(): Envelope
    {
        return new Envelope(
            subject: "Receipt for order #{$this->order->number}",
            replyTo: [new Address('billing@yourdomain.com', 'Acme Billing')],
        );
    }

    public function content(): Content
    {
        return new Content(
            view: 'mail.receipt',        // HTML Blade view
            text: 'mail.receipt-text',   // plain-text alternative
        );
    }

    public function attachments(): array
    {
        return [
            Attachment::fromStorage("invoices/{$this->order->number}.pdf")
                ->as("invoice-{$this->order->number}.pdf")
                ->withMime('application/pdf'),
        ];
    }

    public function headers(): Headers
    {
        return new Headers(text: [
            'X-PostStack-Tags' => 'receipt,transactional',
            'X-PostStack-Idempotency-Key' => "receipt-{$this->order->id}",
        ]);
    }
}

<?php
namespace App\Notifications;

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Notifications\Messages\MailMessage;
use Illuminate\Notifications\Notification;

class InvoicePaid extends Notification implements ShouldQueue
{
    use Queueable;

    public function __construct(public string $amount) {}

    public function via(object $notifiable): array
    {
        return ['mail'];
    }

    public function toMail(object $notifiable): MailMessage
    {
        return (new MailMessage)
            ->subject('Payment received')
            ->greeting("Hi {$notifiable->name},")
            ->line("We received your payment of {$this->amount}.")
            ->action('View invoice', url('/billing'));
    }
}

// $user->notify(new InvoicePaid('€15.00'));

<?php
// config/services.php
'poststack' => [
    'key' => env('POSTSTACK_API_KEY'),
],

// app/Services/PostStack.php
namespace App\Services;

use Illuminate\Http\Client\ConnectionException;
use Illuminate\Http\Client\RequestException;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Str;

class PostStack
{
    public function send(array $payload, ?string $idempotencyKey = null): string
    {
        return Http::withToken(config('services.poststack.key'))
            ->withHeaders(['Idempotency-Key' => $idempotencyKey ?? (string) Str::uuid()])
            ->acceptJson()
            ->timeout(10)
            // retry network errors, 429 and 5xx — never 4xx validation errors
            ->retry(3, 1000, fn ($e) => $e instanceof ConnectionException
                || ($e instanceof RequestException
                    && ($e->response->status() === 429 || $e->response->serverError())))
            ->post('https://api.poststack.dev/emails', $payload)
            ->throw()
            ->json('id');
    }
}

// usage
$id = app(\App\Services\PostStack::class)->send([
    'from' => 'Acme <hello@yourdomain.com>',
    'to' => ['user@example.com'],          // always an array
    'subject' => 'Hello from Laravel!',
    'html' => view('mail.welcome-html', ['user' => $user])->render(),
    'text' => 'Welcome to Acme!',
    'tags' => ['welcome'],
]);

# .env (local) and .env.testing
MAIL_MAILER=log

// tests/Feature/RegistrationTest.php
use App\Mail\WelcomeMail;
use Illuminate\Support\Facades\Mail;

public function test_welcome_email_is_queued(): void
{
    Mail::fake();

    $this->post('/register', [/* ... */]);

    Mail::assertQueued(WelcomeMail::class, fn ($mail) => $mail->hasTo('ada@example.com'));
}