UserController.php

    private function sendWelcomeEmail(User $user)
    {
        // Enabling pretend mode for developers
        // Writing email in logs instead of really sending them.
        if (App::environment('development')) {
            Mail::pretend();
        }

        $data = [];

        // transfering only the needed properties to the closure
        // as queue has a 64kb limit: http://stackoverflow.com/a/21299503
        $user_email = $user->email;
        $user_fullname = $user->firstname . ' ' . $user->lastname;

        Mail::queue('success_email', $data, function($message) use ($user_email, $user_fullname)
        {
            $message->to($user_email, $user_fullname);
        });
    }