This is hardly new, and it goes far beyond spam emails. Most of the content produced and consumed on the internet is now done by machines. A human may or may not benefit from directing a machine to do this, and the ways they do are often highly opaque, with several layers of indirection. It doesn't take a genius to see that this is ushering in a new era of scams and spam.
"AI" companies are responsible for this mess. They should be held accountable for digging us out of it.