This enquiry asked me to respond to his personal email -- don't! Respond through the rental site form so the fraudster does not get your email.
Next he sent me an "acceptance" email with a link to "verify the exact location" of our villa. I knew this was fraud, did not click.
Here is the relevant part of the header with his email:
Received-SPF: pass (google.com: domain of greg.riching09@gmail.com designates 2607:f8b0:4001:c06::243 as permitted sender) client-ip=2607:f8b0:4001:c06::243;
Linkback: https://www.enjoykalkan.com/forum/index.php?topic=13158.0