1. Open your FirstClass desktop
2. On the menu at the top of the screen, click on Edit menu --> Preferences
3. Click on the tab called Messaging and them make sure you are on the page called Mail Rules:
4. Near the top of the page you will find a box titled "Reply Preference:"
5. Click on the drop down menu and change the setting to "Reply Sender"
6. Click on the Apply button at the bottom of the page and then on the "OK" button
You have now changed the default FirstClass setting to reply only to the sender of a message.