In a group email context, when is it appropriate to use "reply all"?

Using "reply all" is appropriate when making suggestions that involve everyone in the group because it ensures that all recipients receive the information and can contribute to the discussion. This fosters collaboration and keeps everyone on the same page, which is essential in a group setting. When a suggestion is made that may affect the entire group, responding to all reinforces the collective decision-making process and encourages feedback from all participants.

In contrast, confirming receipt of the email may only require a response to the original sender, as a reply-all doesn't add value in this case. Making personal remarks also doesn't need the attention of the entire group, as it may clutter their inboxes with irrelevant content. Similarly, addressing an unclear email should typically be directed to the sender alone, to avoid confusion among the group that may not have the same questions or concerns.