Spam...or danger??

So I'm checking my email below, and get this message below:

Alex, is there any possibility of doing 2:00 or does that really screw you up? I may need to do a four-way session with another therapist at 3...
H

"Eye of the Burning Man (A Mick Callahan Novel)"Five Star Mysteries, ISBN 1-59414-381-1November, 2005

Of course I immediately assume this is spam. After all, I've seen plenty of emails that draw you in with a mysterious/intriguing subject, but then have a link where you can buy "herbl v1agra" or somesuch. And yet, this email seems...too personal. So I do a google search of the sender's email address, and find that it's actually posted on some discussion groups for mysteries. Following that trail, I eventually find that yes in fact, the person who sent this to me(or at least, the person who's email was used to send this to me) is in fact a real person, and resides online here. In fact, he's the very author of the book mentioned above at the end of the email.

So the question is...why is he writing me about a therapy session? Where did he get my email address from, and how on Earth could I have some appointment of some kind with someone I've never heard of before now? Very, very interesting. And somewhat ironic, that a man who writes mysteries would present me, out of the blue, with a mystery of my own. The question now of course is should I email and get to the bottom of this little mystery? Or does that risk my entry into a dark and foreboding work of mental illness and obsession? I await your comments.