Namex spam?

Made an offer on a domain Parked on Namex, and never got a response.

Many days later, found several responses in my spam folder. The buyer asked for ridiculous amount of money, and I stopped negotiation very quickly. Problem is, I got a counteroffer mail everyday, and every time Gmail sent it to spam inbox. I did open the mail a few times, but the price has always been the same.

Is this normal? Or is Namex just persistent in making sure all its mail always got labeled as spam?