SCN has direct messages, but it is only for members who are following each other.
As you see I have my mail ID visible in my profile, so people can even reach me by mail. It is still up to me if I answer or not.
Sometimes it is useful, where people do not want to share screen shots in public, somehow they trust me 
If I am approached with questions for which the answer is in the forum, then I certainly react identically like I do as moderator in the forum, with please search.
To be honest, it is in average maybe 4 mails per week. They probably know that I am more active in the forum than in mailbox.