There's a few different scams that I've ran into.

1. If selling a vehicle or motorcycle, they will email you and ask you to pay for a VIN report (from a link that they send). The VIN website is a fake and will steal your CC info if you enter it.
2. You'll get an email to the tune of "Hey, been having trouble with my messenger, please email me at johndoe(at)gmail.com. They never put in the @ symbol. Email phishing scam.
3. The fake cashiers checks. Scammers will often use broken english, and always refer to what you're selling as "the item".

Cash only, no exceptions.