Send emails with PHP / Laravel

Learn how to send transactional emails using PostStack and PHP / Laravel.

PHP ships with cURL in the core, so you can talk to PostStack without Composer if you want a minimal dependency tree. For Laravel, configuring PostStack as the mail transport in `config/mail.php` is usually the cleanest path — every `Mail::send`, `Notification::route('mail', ...)`, and queued mailable goes through PostStack with no per-call changes.

1. Install the SDK

bash

# No external packages needed — uses built-in cURL

2. Initialize the client

php

$apiKey = getenv('POSTSTACK_API_KEY');
$baseUrl = 'https://api.poststack.dev';

3. Send an email

php

<?php
$apiKey = getenv('POSTSTACK_API_KEY');

$payload = json_encode([
    'from' => 'hello@yourdomain.com',
    'to' => ['user@example.com'],
    'subject' => 'Hello from PHP!',
    'html' => '<h1>Welcome!</h1>',
]);

$ch = curl_init('https://api.poststack.dev/emails');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => $payload,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer ' . $apiKey,
        'Content-Type: application/json',
    ],
]);

$response = curl_exec($ch);
curl_close($ch);

echo $response;

4. Handle errors

PHP / Laravel idioms for error handling, retries, and structured logging when calling the PostStack API.

php

<?php

class PoststackException extends RuntimeException {
    public int $statusCode;
    public ?string $requestId;
    public function __construct(int $statusCode, string $message, ?string $requestId = null) {
        parent::__construct($message);
        $this->statusCode = $statusCode;
        $this->requestId = $requestId;
    }
}

function send_email(array $payload, int $attempts = 3): array {
    $apiKey = getenv('POSTSTACK_API_KEY');

    for ($i = 0; $i < $attempts; $i++) {
        $ch = curl_init('https://api.poststack.dev/emails');
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_POST => true,
            CURLOPT_TIMEOUT => 10,
            CURLOPT_POSTFIELDS => json_encode($payload),
            CURLOPT_HTTPHEADER => [
                'Authorization: Bearer ' . $apiKey,
                'Content-Type: application/json',
            ],
            CURLOPT_HEADER => true,
        ]);
        $response = curl_exec($ch);
        $status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        curl_close($ch);

        if ($status >= 200 && $status < 300) {
            return json_decode($response, true);
        }
        if ($status === 429 || $status >= 500) {
            sleep(2 ** $i);
            continue;
        }
        throw new PoststackException($status, (string) $response);
    }
    throw new RuntimeException('send_email retries exhausted');
}

Framework integrations

Laravel mail transport

In `config/mail.php`, add a `poststack` mailer with `transport: smtp`, `host: smtp.poststack.dev`, `port: 587`, `encryption: tls`, `username: poststack`, `password: env("POSTSTACK_API_KEY")`. Set `MAIL_MAILER=poststack` in `.env`. Every `Mail::send` and `Notification::send` now flows through PostStack — no controller changes needed.

Laravel queued mail

Queued mailables (`ShouldQueue`) work unchanged. The queue worker picks up the job, opens an SMTP connection to PostStack, and sends. Use Horizon to monitor throughput and retry failures.

Symfony Mailer

Configure the `MAILER_DSN` to `smtp://poststack:%env(POSTSTACK_API_KEY)%@smtp.poststack.dev:587`. Inject `MailerInterface` into your services and call `$mailer->send($email)`.

WordPress

Install WP Mail SMTP, FluentSMTP, or any SMTP plugin. Point it at `smtp.poststack.dev:587` with username `poststack` and your API key. All transactional WordPress emails (admin alerts, password resets, WooCommerce order emails) start delivering through PostStack.

Common pitfalls

Disabling SSL verification
`CURLOPT_SSL_VERIFYPEER => false` opens you to MITM attacks. Always leave SSL verification enabled — the PostStack TLS cert is from a public CA.
Misconfiguring `MAIL_FROM_ADDRESS`
Your `From` address must be on a verified domain. Laravel’s default `hello@example.com` is rejected. Update `MAIL_FROM_ADDRESS` in `.env` to your verified domain.
Holding cURL handles open per-request
For low-volume PHP apps the per-request handle is fine. For high-volume CLI workers, reuse a single cURL handle with `curl_init` once and `curl_setopt` per request to amortise the TLS handshake.

Notes

Uses built-in PHP cURL — no Composer packages required
For Laravel, you can also configure PostStack as an SMTP transport in config/mail.php

FAQ

Do I need Composer or a package?

No. PHP’s built-in cURL is enough. For Laravel, you can also configure SMTP without adding a package.

Can I use this with WordPress?

Yes — use WP Mail SMTP or FluentSMTP. Point it at smtp.poststack.dev:587 with the API key as the password. Every WordPress email (admin, WooCommerce, contact-form-7) flows through PostStack.

What about Laravel queued mailables?

They work unchanged. The queue worker handles the SMTP connection and retries. Use Horizon for visibility.

Ready to send emails with PHP / Laravel?

Create a free account and get your API key in under a minute.