You can reply by the footer, as long as your group is set up to allow this.
Via Group Page:
You can reply by selecting Private (right side below the message box where you are typing). Again this is dependent on your group's settings.
If you are replying to an emailed message -
- Click on an email footer to go to the message on your group.
- Type your reply.
- Click on Private. That changes the command so it says reply to sender. Click if you want to BCC'd to yourself.
Or you can reply to any group member who has permitted their contact info to be in the Directory - left menu. There is a link beside their name.