[Mailer] Handle null & empty to/cc/bcc/reply-to addresses

[mote0230]

Description

Similar to this drupal issue: Allow removal of to/cc/bcc/reply-to addresses (after they are added to an email) (not sure why they didn't try to upstream their patch)

Currently I have to refactor my code from

$message = (new TemplatedEmail())
                ->subject('foo')
                ->from('bar')
                ->to($obj->getEmail())
                ->cc($obj->getCc())

To

 $message = (new TemplatedEmail())
                ->subject('foo')
                ->from('bar');
 if(!is_null($obj->getCc()) && !empty($obj->getCc())) {
     $message->cc($obj->getCc())
}
 if(!is_null($obj->getEmail()) && !empty($obj->getEmail())) {
     $message->to($obj->getEmail())
}

And so on, every time. That's a lot of repeating yourself.

Current behavior is to throw an exception.

Swiftmailer handled this, and it seems more logical to me to handle it there.

Additionally, it would fix the problem in the linked drupal issue. It also contains a patch that can probably be used as a starting point.

Example

No response