1. From the system tray, near the system clock, click on the Kerio Personal firewall to open the Firewall Configuration window.
2. Click on Network Security and choose the Applications tab.
3. Based on your Any Other Application setting, when a new application is trying to access the Internet through the firewall you may recieve a prompt or the application will be permitted access to the Internet automatically. When you use MSN Messenger, it will automatically be added to the Applications list. Once added, you will have to ensure it has full access to connect to the Internet.
4. In the Applications list, verify the settings for MSN Messenger. MSN Messenger must be set to Permit in the In and Out sub-columns of both the Trusted and Internet columns
5. To modify settings, select the MSN Messenger entry and choose Edit to open the Connection Settings window.
6. In the Connection Settings window ensure Incoming Connection and Outgoing Connections are all set to Permit. Click OK to close the window.
7. To remove the application rules for Messenger, select the Messenger rule from the Applications Network Security list and click on Remove.
For more information, refer to the Kerio Personal Firewall website.