Postal

A modern, driver-based email library for CodeIgniter 4.

Postal replaces CodeIgniter 4's monolithic Email class with a clean transport-driver architecture: compose a message once and send it through SMTP, Sendmail, PHP mail(), Amazon SES, or a failover chain — without changing your application code. It keeps the familiar CI4 email API working for a painless migration, and it's fully testable without ever sending a real message.

Highlights

• Driver-based transports — change how mail is delivered through configuration, not code.
• Amazon SES — deliver through SesV2 with SigV4 signing; no SMTP relay required.
• DKIM signing — sign outbound messages at the library level with a one-line config addition.
• Failover chain — wrap mailers in a priority-ordered fallback so a provider outage doesn't drop mail.
• Suppression lists & unsubscribe — filter recipients before send and auto-inject List-Unsubscribe headers.
• Inline image embedding — local paths and data: URIs in HTML are automatically rewritten to cid: attachments.
• Mailable classes — reusable, class-based emails with browser preview in development.
• Drop-in friendly — existing service('email') calls keep working via a compatibility adapter.
• Zero required dependencies — PHP standard extensions only; no database, queue, or view renderer needed to send mail.
• Built for testing — a fake transport and expressive assertions verify mail in PHPUnit with no network access.

A quick taste

<?php

use Myth\Postal\Email;

$email = (new Email())
    ->from('you@example.com', 'Your Name')
    ->to('user@example.com')
    ->subject('Welcome aboard')
    ->html('<p>Glad to have you with us.</p>');

$result = service('mailer')->send($email);

Continue to Quick Start to get started.