(…) Assume best intent simply means that you opt to give people the benefit of the doubt, rather than assuming that they are out to get you. If someone sends a seemingly rude email, we can assume that they want to embarrass us in front of the people copied or we can assume that they were in a hurry to send the email and didn't realize the negative tone.

Very little good can come from assuming the former, especially when that's coupled with an equally rude reaction, but tremendous good can come from training your staff to assume the best of their colleagues. (…)