This problem arises in many "newsgroups". If I make a request for assistance / information in a newsgroup I usually say something like "e-mail me direct as well as posting here".

Reasons:

1. e-mail direct so that I get the benefit of the groups experience even if I can't join the group for some time (I move around a lot and not all the sites I go to have a comprehensive set of newsgroups).

2. post to newsgroup so that all gain the benefit - as dick greenhaus says, that's the point of most newsgroups

This imposes a slightly greater burden on the person providing the information, but with cut'n'paste it's probably not to onerous.

Just a thought...