> at least not openly. In other words, they could have concealed the location of their services.
You can't provide a paid commercial service while hiding your business entity. And, on top of that, DNS and SMTP make this basically impossible technically as well. So what you're looking for is, at least when it comes to email, something that doesn't and can't exist.
> You can't provide a paid commercial service while hiding your business entity.
You absolutely can. This is how many entities on the dark web function. And in fact, so do many entities on the clear web (see the RBN and its successors as an example).
You can't provide a paid commercial service while hiding your business entity. And, on top of that, DNS and SMTP make this basically impossible technically as well. So what you're looking for is, at least when it comes to email, something that doesn't and can't exist.