I assume you're trying to e-mail a member with respect to a table he built. The best thing is to send this person a Personal Message (PM). Not all users have set up their account on NCWW to allow e-mail from other users.
To send a message, find a post by that person and click on the person's name (which would be left of the post). That will bring up a little menu where you should see an option for a Personal Message, and maybe also an option to e-mail.
The other way is to go to the Member List (menu item in the brown bar), and locate the person in question. Click on the name. Then, click on the tab "Contact Info" to find options to PM/ e-mail the person.
Don't hesitate to ask more questions if this doesn't help - contrary to popular belief, this stuff is NOT easy.