Email Plus - Concept
This concept evolved emails and message board threads into one interface. It attempted to solve the common problem of having multiple replies to an email. The concept is simple, when the recipient replies to the email, a new email is not sent, rather the orignal email just indicates where the comment is.
Each topic is defined by a paragraph, and replies are made at the paragraph level. The email can be viewed fully expanded (left), or in a tree view (right), which is similar to a traditional message thread.