If I just add the header in the mailable:
public function headers()
{
return new Headers(
text: [
'Return-Path' => config('mail.from.address'),
],
);
}
I get an error:
The "Return-Path" header must be an instance of "Symfony\Component\Mime\Header\PathHeader" (got "Symfony\Component\Mime\Header\UnstructuredHeader").