Between Meetings is a feature found on the Premium and Ultimate plans.
When a new comment is added to either a Between Meeting Report or a Flying Minute (aka Circular Resolution), Board Members will receive an email notification that a comment has been created or replied to.
You can post an answering comment by replying to that email (an example from Outlook is below).
Note: If you click on the blue heading of the Report, BoardPro opens into Between Meeting Report, where you also have the option to respond.
If you want to turn off notifications for this particular Report, you can just open it in BoardPro and click on the email notification icon next to the Comments at the bottom.
Note: The report owner will not be able to turn off notifications.