A bigger emphasis on conversation-cards like panels

[hanaral]

I just saw the way that the Hey.com UX is like, and I think its something the Mail app could aspire to be like. I really like conversation based UI, and often use my email just to messege people.
Maybe the list at the side could be similar to the skeuomorph way that the wingpanel notifications look, since it's the only built in communication app. I don't see how it could clash with preexisting HIG, and the switch to have all conversations from the same person stacked could just be a toggle in the headerbar.