[elric]

And of course, the email chain gives everyone time to think on the problem and construct a sensible reply, without interrupting anyone.

As opposed to some manager walking up to your desk while you're neck deep in concentration, only to ask you a retarded question that should have been an email.

[A4ET8a8uTh0_v2]

And, not mentioned explicitly anywhere in the discussion, email is a proof of sorts come a dispute time. Chat in the hallway won't be captured in a deposition or at least not as much more than 'he said, she said'.