Preview Mail without Mailables

You can also preview your email without Mailables. For instance, when you are creating notification, you can specify the markdown that may be use for your mail notification.

use Illuminate\Notifications\Messages\MailMessage;
 
Route::get('/mailable', function () {
    $invoice = App\Invoice::find(1);
    return (new MailMessage)->markdown('emails.invoice-paid', compact('invoice'));
});

You may also use other methods provided by MailMessage object such as view and others.

Tip given by @raditzfarhan