Hi there,
I want to send another user a private message/email,
How can I do that?

You can't.

Alex has come in for a bit of flak regarding this forum (which was revamped some time ago to make it part of the main website) but I think it's best to just wait now and see what happens after the takeover.

First order of business after the takeover should be to go back to the old forum. That would be one massive improvement right there.