Question on leaving negative itrader

I finally had my first problem...not bad for a year of positive experiences.
I recieved a PM from one of my threads in the BST forum I created offering content creation.

I was PMed by a guy who wanted 3 articles. I told him the price, he agreed. I sent the articles. He has not contacted me nor payed since them.

Question: Since he didnt post in the thread (only PM) can I leave feedback?
I never ask people to post in my thread, because I do not want to be accused of bumping...was this a mistake.

 

As long as the thread initiated the deal, you can leave iTrader. Both parties don't have to actually post in the thread, but one of those involved does have to be the thread's OP.