Contact Author for K2 is a plugin that permit to any visitor to your site to contact the K2 Author of the specific item he is in . It is suitable for anyone that needs his visitor to contact multiple authors without their email to be public. Noone can see Authors email but anyone can still contact them.
Updated and now use html5 form . Options added for custome css, tooltip , and required fields.
The extension is good. It can be improved but the developer offer very good support. I wanted some minor changes and he was willing to help . Also this extension is very easy to setup and work out of the box.