Earlier quoted context omitted.
Okay I played fast and loose, but I meant this: By definition of the length of a day, if you are sending any serious volume of emails then most of them are going to be short.
Given the mess long email conversations become, if as CTO you're sending that many short emails I'd say you're using the wrong medium. A PM tool makes it much easier IME for the team to keep track of, and on top of, messages relevant to their projects, and reference them later.
Email is the universal medium. If I need to search for some history, I start with email since it is the most common. Skype we use for private and urgent chat. Campfire we use for general development chat. Basecamp we use for archivable product decision making. All of those have their uses.
I can't begin to think why you believe all my short emails are better suited for chat, but without context it's extremely, extremely ignorant and wrong.