Email has been slowly balkanising itself for years now. By way of example, I know personally several people who run mail relays and not only refuse to relay messages from and to Google email servers but even refuse to _receive_ emails addressed to their users from GMail addresses. All of this on what is essentially a political objection.
In the fullness of time, email will fail as a communication medium because of these situations. I don't think that Google will mind terribly when it does.
In the fullness of time, email will fail as a communication medium because of these situations. I don't think that Google will mind terribly when it does.