Don't fret too much about spam messages. Trust me, I have several domains that I get various emails about... most of which are crap. There are people/companies out there watching and monitor domain sales and targeting messages to people getting certain domains trying to get you to buy something or click some link, etc. DO NOT click a link in any of those emails, don't even reply. Do some research on that message and you may very well find that other people are getting the exact same type of email as what you got.
There is actually a recent thread on the forum in the Legal Issues & Disputes section titled "Another One - Appraisal Scam"... that is one example of emails that people get, etc.