// In some controller
public function sendEmail(Request $request)
{
Config::set('mail.host', 'smtp1.sample.com');
Mail::to($request->user())->send(new OrderShipped($order));
Config::set('mail.host', 'smtp2.sample.com');
Mail::to($request->user())->send(new OrderShipped($order));
}
In the end you can write a service that actually handles this for you, for example