When should you reply all on a disagreement email?

Reply all when the decision affects everyone on the thread and the record needs to show that the objection was raised. Reply to the sender alone when the disagreement is about how they wrote something, when you are testing whether you have understood the plan, or when a wide audience would make it harder for either of you to change position. A useful default: facts to the thread, feelings to the sender.

Disagreeing by Email in English: Softening Lines That Still Land →