marko/mail-log

Log-based mail driver --- writes emails to the log instead of sending them, ideal for development and testing. Implements MailerInterface from marko/mail by writing email details to the logger rather than delivering them. Message metadata (from, to, subject, attachment count) is logged at info level; full HTML/text bodies are logged at debug level. Every send() call returns true since no delivery can fail.

Installation

composer require marko/mail-log

This automatically installs marko/mail and marko/log.

Usage

Automatic via Binding

Bind the mailer interface in your module.php for development:

module.php

use Marko\Mail\Contracts\MailerInterface;
use Marko\Mail\Log\LogMailer;

return [
    'bindings' => [
        MailerInterface::class => LogMailer::class,
    ],
];

Or conditionally bind for development only:

module.php

use Marko\Container\Contracts\ContainerInterface;
use Marko\Mail\Contracts\MailerInterface;
use Marko\Mail\Log\LogMailer;
use Marko\Mail\Smtp\SmtpMailer;

return [
    'bindings' => [
        MailerInterface::class => SmtpMailer::class,
    ],
    'boot' => function (ContainerInterface $container): void {
        if (($_ENV['APP_ENV'] ?? 'production') === 'development') {
            $container->bind(
                MailerInterface::class,
                LogMailer::class,
            );
        }
    },
];

What Gets Logged

When you send a message, the log output includes:

[2025-01-15 10:30:00] app.INFO: Email sent {"from":"noreply@example.com","to":["user@example.com"],"subject":"Welcome!","has_html":true,"has_text":false,"attachment_count":0}
[2025-01-15 10:30:00] app.DEBUG: Email body (html) {"body":"<h1>Welcome!</h1>"}

The info-level entry captures metadata --- from address, recipients, subject, whether HTML/text bodies are present, and attachment count. If the message includes CC, BCC, or attachments, those details are included as well (attachment name, size, and MIME type). The debug-level entries log the full message body for each content type (text and/or HTML).

For sendRaw(), the info entry logs the recipient and raw content length, while the debug entry logs the full raw content.

Your code stays the same regardless of driver:

use Marko\Mail\Contracts\MailerInterface;
use Marko\Mail\Message;

class WelcomeMailer
{
    public function __construct(
        private MailerInterface $mailer,
    ) {}

    public function sendWelcome(
        string $email,
    ): void {
        $message = Message::create()
            ->to($email)
            ->from('noreply@example.com')
            ->subject('Welcome!')
            ->html('<h1>Welcome!</h1>');

        $this->mailer->send($message);
    }
}

API Reference

LogMailer

Implements MailerInterface. See marko/mail for the full interface contract.

Method	Description
send(Message $message): bool	Log message metadata at info level and body at debug level; always returns true
sendRaw(string $to, string $raw): bool	Log recipient and raw content length at info level, full content at debug level; always returns true

The constructor accepts a single dependency:

use Marko\Log\Contracts\LoggerInterface;

public function __construct(
    private LoggerInterface $logger,
) {}