>it only takes one mis-typed email address and the entire conversation could be leaked. Then perhaps the people involved should be encouraged to trim all the o

>it only takes one mis-typed email address and the entire conversation could be leaked. Then perhaps the people involved should be encouraged to trim all the old junk from the bottom of their messages... for exactly the reason you have described. A discussion between 15 people is inevitably going to get leaked to some extent no matter what the medium. Sometimes you can break things into smaller discussion groups. You could set up a private web forum. That's probably it for web based stuff.