Upgrade to Laravel 5.3 - Mail::send now returns null from Mandrill

I'm upgrading from Laravel 5.2 to 5.3 but since doing so the Mail::send function no returns null when sending via Mandrill.

I had the same issue in Laravel 4.2, but it seems this functionality was then added when upgrading to version 5.

$response = Mail::send($template, $email, function($message) use($subject)
{
    $message->to('test@example.com')->subject($subject);
});

dd($response)

Message sends fine, but the response is null where is gave the message ID/content in 5.1 & 5.2 before the upgrade

I can't understand why they would add the feature then remove it again?

via Chebli Mohamed