Have you ever considered assigning each new person admitted to
the rolls an experienced "buddy," a Big Sister or Big Brother?
Assigning these in such a way as to stick to active posters and
not overload anyone is something that could be done automatically,
and I don't think that the active veterans would mind.
I have to admit I find your experience sobering, that no matter
what manner of instructions you wrap a MailTo: button in, people
will push the button and not read the instructions. But that's
the American public, when I think of it. I tend to agree with
you that mechanical fixes have a poor prognosis for some of these
problems. That's what sends me looking for social approaches
like the "Buddy" method.