PornBox.com

Sorry if this is a stupid question, but how do I send some one a private/direct message on the forum?

You cant.
This function has been abolished many years ago.
Only way around that is to ask the person you want to contact for an e-mail address or their social media or Telegram.

Thanks, thought might be the case. I signed up a few years ago but only just started posting!

I got a tremendous treasure of PMs deleted when they abolished that PM/DM service.

But post factum I guess too many porn users misused that option for file-sharing set-ups and some maybe also for social media scouting. At that time more porn girls posted here still. So some also might have got awkward PM/DM. Many users seem not to know barriers, not to grasp that porn girls are humans like you and me, too.