The primary form of communication among teams co-located with each other should never be email. It should be face-to-face.
We overuse email to a point that if teams stop using email to talk to each other, we will get things done five times faster and ten times more effectively. For every email we send, whether to clarify a question or ask for a status update, we have introduced a unpredictable delay in our workflow and we can do nothing except context switching to do something else rather than focussing on finishing the task at hand.
Email is good when something needs to be documented. It is good when communicating with team members from different timezones. It is good when something needs to be communicated to a large audience. It is not good for two people to communicate with each other. The gift of spoken language, which all of us are blessed with, is more suited.
Let us not email ourselves to mediocrity.