This week I helped a friend of a friend understand the reality of managing a team for the first time. I mentioned a few things about productivity offhand they found useful. Reproduced here is how I handle the onslaught of incoming email:
1. All communication must be on mailing lists to create a body of searchable knowledge and overcome the bus factor*.
2. Never reply to an email if anyone else on the thread also knows the answer.
3. Always reply when you have information that nobody else does.
4. If something is important they will email you repeatedly, IM, call, show up in person, etc.
5. Worst-case: Wait a day (or week, or month) and finally reply to an email yourself.
If I didn't do these things I would never find time to design, review, write code.
* Direct emails for sensitive things are fine, but that's the only exception.