I and some of my friends have gotten emails from scammers who say they want to buy several paintings from my artist website, but are moving and want to use a bank check- or something similar. What I have done is reply that I will only accept payments through PayPal. Then I never hear from them again. Bitcoins would also work. The problem with testing it out by accepting a check or Bank order and depositing it in case it is for real is that you will get hit by a hefty fee from the bank if it bounces.