There are two methods. First - when the forum page is open- click on the name of the person you wish to e-mail. The new window will open-click send and e-mail.It will show the name of the recipient and sender.Compose your mail.If you wish the recipient to obtain your e-mail address tick the small box and Send your e-mail.
The other method is when the forum page is open-click My profile at the top. When the window opens -click send and e-mail.-Click on the recipient.-A drop down window will show all the registered users. Select and proceed as above. Try sending yourself mail to find out how it works. Hope this will help. Regards from down under.