CakePHP Symfony Mailer Bridge

josbeir/cakephp-symfony-mailer provides a CakePHP 5 mail transport that hands CakePHP's rendered MIME messages to Symfony Mailer.

CakePHP remains responsible for rendering the message. Symfony Mailer is responsible for delivery, so multipart alternatives, attachments, inline cid: images, and CakePHP headers are preserved.

Why use this bridge?

Keep CakePHP's mailer API, templates, localization, and MIME composition while gaining Symfony Mailer's transport ecosystem:

• Use provider bridges and HTTP API transports for services such as Mailgun, Amazon SES, Postmark, and SendGrid.
• Switch between Mailpit or SMTP locally and an API-backed provider in production through configuration alone.
• Configure Symfony's failover and round-robin transports without changing application mailers.
• Preserve multipart text/HTML messages, attachments, inline cid: images, custom headers, and envelope recipients.
• Keep delivery concerns out of application mailers: CakePHP builds the message and Symfony Mailer delivers it.

Symfony Mailer documentation

This bridge delegates transport selection and delivery to Symfony Mailer. See the Symfony Mailer documentation for DSN syntax, built-in transports, TLS settings, failover, and round-robin delivery.

For provider-backed delivery, see Using a 3rd-party transport. Install the provider bridge for the mailer you choose. API-based transports also require Symfony's symfony/http-client package; provider bridges do not necessarily install that optional HTTP client themselves. SMTP, Sendmail, and Native transports do not need it. This plugin remains provider-agnostic and supports any transport accepted by Symfony Mailer.

Commonly supported mailers

Symfony Mailer provides provider bridges for commonly used services including:

Mailer	Symfony bridge
AhaSend	symfony/aha-send-mailer
Amazon SES	symfony/amazon-mailer
Azure Communication Services	symfony/azure-mailer
Brevo	symfony/brevo-mailer
Mailgun	symfony/mailgun-mailer
Mailjet	symfony/mailjet-mailer
MailerSend	symfony/mailer-send-mailer
Mailtrap	symfony/mailtrap-mailer
Microsoft Graph	symfony/microsoft-graph-mailer
Postmark	symfony/postmark-mailer
Resend	symfony/resend-mailer
SendGrid	symfony/sendgrid-mailer

Symfony also includes built-in smtp, sendmail, and native transports. The provider list changes over time; consult the Symfony provider table for the complete, current list and each provider's DSN format. Gmail's transport is intended as a convenience for development and testing, not as a production delivery service.

Requirements

• PHP 8.2 or newer
• CakePHP 5.2 or newer
• Symfony Mailer 7.4 or newer within the 7.x series

Installation

composer require josbeir/cakephp-symfony-mailer
bin/cake plugin load CakeSymfonyMailer

Install the Symfony provider bridge and any additional component required by the chosen DSN. The Mailgun bridge depends on symfony/mailer, but its HTTP API transport does not pull in symfony/http-client automatically. For Mailgun API delivery, install both explicitly:

composer require symfony/mailgun-mailer symfony/http-client

Configuration

Configure the transport through CakePHP's normal EmailTransport settings:

use CakeSymfonyMailer\Mailer\Transport\SymfonyMailerTransport;

'EmailTransport' => [
    'default' => [
        'className' => SymfonyMailerTransport::class,
        'dsn' => env('MAILER_DSN'),
    ],
],

Examples of Symfony DSNs include:

# Mailgun API (install symfony/mailgun-mailer and symfony/http-client)
MAILER_DSN='mailgun+https://API_KEY:DOMAIN@default'

# SMTP
MAILER_DSN='smtp://user:password@smtp.example.com:587?require_tls=true'

# Symfony failover transport
MAILER_DSN='failover(smtp://user:password@smtp.example.com:587 smtp://user:password@smtp-backup.example.com:587)'

Follow Symfony Mailer's DSN escaping rules for credentials containing reserved URI characters.

Development

composer install
composer test
composer cs-check
composer stan
composer rector-check

The checks run PHPUnit, PHPCS, PHPStan at level 10, and Rector in dry-run mode. Coverage is collected separately with:

composer test-coverage

The CI coverage job requires a coverage driver and publishes a Clover report for src/.

License

MIT. See LICENSE.