One way to send a private message now is to click on someone's name which will open up their profile, and if they have included their e-mail address there will be a "Send e-mail" link there that you can use to send them an e-mail.

Write your own e-mail address inside the message somewhere for a reply, because I think it will get sent from the forum software with a generic moi@moi3d.com reply address by default.

- Michael