Set "Email Visible to Other Members" to "No, accept email anonymously" then save changes and you should be good to go.
Generally we would encourage people to post on site as questions tend to grow from the one originally asked. Thats espechially true of people new to this as there have been times when we've told people that they're actually asking the wrong question or the question asked doesn't go far enough.
Besides that, if you take questions and answers off site they are only helping one person rather than the hundreds who view posts on the site.
kindest regards,
Shaun.
__________________
Shaun
Responses are not meant as a substitute for professional advice. Answers are intended as outline only the advice of a qualified professional with access to all relevant information should be sought before acting on any response given.