README

A drop-in Laravel package that automatically signs all outgoing emails with DKIM. No changes to your existing Mailables, Notifications, or any mail-sending code required — just install, configure your key, and every email gets signed transparently.

Uses Symfony's built-in DkimSigner under the hood.

Installation

composer require shaffe/laravel-dkim

The service provider is auto-discovered via the composer.json extra configuration.

Configuration

Publish the config file:

php artisan vendor:publish --tag=dkim-config

Add these variables to your .env:

DKIM_ENABLED=true
DKIM_PRIVATE_KEY=/path/to/your/private.key
DKIM_DOMAIN=example.com
DKIM_SELECTOR=my-selector
DKIM_PASSPHRASE=

DKIM_PRIVATE_KEY accepts either a path to a PEM key file or the raw PEM key as a string.

Choosing a Selector

We recommend using a custom selector instead of default. The default DKIM key (default._domainkey.example.com) is often managed by your hosting panel (Plesk, cPanel, etc.) and may be regenerated during system upgrades or configuration changes — which would silently break your application's DKIM signing.

Using a dedicated selector like laravel, or app-mail gives you several advantages:

• Your key is independent from the system-managed one and won't be affected by server-side changes.
• It clearly identifies the source of signed emails (useful when multiple services send from the same domain).
• You can rotate or revoke the key without impacting other services.

Key Generation

Generate a dedicated key pair for your selector:

openssl genrsa -out my-selector.dkim.private 2048
openssl rsa -in my-selector.dkim.private -out my-selector.dkim.public -pubout -outform PEM

DNS Setup

Add a TXT record for your selector on the sending domain:

my-selector._domainkey.example.com  IN  TXT  "v=DKIM1; k=rsa; s=email; p=<your_public_key_base64>"

The p= value is the content of your public key file, without the -----BEGIN/END PUBLIC KEY----- lines and without line breaks.

Verifying Your DNS Record

You can verify that your DKIM DNS record is correctly set up using MXToolbox:

https://mxtoolbox.com/SuperTool.aspx?action=dkim:example.com:my-selector&run=toolpage

Replace example.com with your domain and my-selector with your chosen selector.

How It Works

The package hooks into Laravel's mail pipeline by listening to \Illuminate\Mail\Events\MessageSending. This event fires right before any email is handed off to the transport, so every email sent through Laravel's mailer (Mailables, Notifications, Mail::raw(), etc.) is automatically signed — without touching a single line of your existing code.