Laravel Mail Logger

App-Providers-Debug.php

<?php declare(strict_types=1);

namespace App\Providers;

use Illuminate\Support\ServiceProvider;
use App\Services\Mail\Logger as LoggerMail;

class Debug extends ServiceProvider
{
    /**
     * @return void
     */
    public function boot()
    {
        $this->logging();
    }

    /**
     * @return void
     */
    protected function logging(): void
    {
        $this->loggingMail();
    }

    /**
     * @return void
     */
    protected function loggingMail(): void
    {
        if (config('logging.channels.mail.enabled')) {
            LoggerMail::listen();
        }
    }
}

App-Services-Mail-Logger.php

<?php declare(strict_types=1);

namespace App\Services\Mail;

use Illuminate\Mail\Events\MessageSending;
use Illuminate\Support\Facades\Event;

class Logger
{
    /**
     * @return void
     */
    public static function listen(): void
    {
        Event::listen(MessageSending::class, static fn ($event) => static::store($event));
    }

    /**
     * @param \Illuminate\Mail\Events\MessageSending $event
     *
     * @return void
     */
    protected static function store(MessageSending $event): void
    {
        $file = storage_path('logs/mails/'.date('Y-m-d/H-i-s').'-'.uniqid().'.log');
        $dir = dirname($file);

        if (is_dir($dir) === false) {
            mkdir($dir, 0755, true);
        }

        file_put_contents($file, (string)$event->message, LOCK_EX);
    }
}

config-app.php

<?php

return [
    'providers' => [

        /*
         * Application Service Providers...
         */
        App\Providers\Debug::class,
    ],
];

config-logging.php

<?php

return [
    'channels' => [
        'mail' => [
            'enabled' => env('LOG_MAIL', false),
        ],
    ],
];