There is few trusted source for selling domains. Flippa, Godaddy Auction, SEDO and few trusted company. Just deal with this companies users. And of course when you will try to sell your domain, use Escrow as a 3rd and middle man. Then there is no chance to lose your domain. If they deny that then you can think they are scammer. Then stay away from them and do not even reply them. Better if you will private your website whois.
Thanks