Mail had too much hype from day #1; something like RIP Airtime on steroids. Usually when it happens it means the board/owners/executive managment is very deeply connected to the media world (like with Color). For that reason alone, it doesn't surprise me they sold it to a large player. Such a quick sale may mean they were dissapointed with their growth but thats speculation. I could be a favor from one exec to another; something like board members of both FB and Instagram selling one to another.

I wouldn't be surprised if Mail will share the faith of Color, Airtime or many others...