I have a non-listed forum where staff can see all posts, but users can only see their own threads.
And the contact list points to this.
A guest has to register in order to contact us, if they're not willing to make that effort I am not interested in listening to what they have to say anyway, clearly it's not important enough. (Sorry, that is just my negative attitude)
A member can post, and if it's a spam bot, I can click on the spam link, and the IP link.