For your remote clients that are not logged on over VPN, it is a best practice to turn on client notifications for the following situations:
You can turn on these notifications by using the location-specific server or, you can select the Mixed control option in the Client User Interface Control Settings. You can customize the settings on the Client User Interface Settings tab.
Virus and security risks
You can turn on these notifications in the Virus and Spyware Protection policy.
Turning on notifications helps to ensure that remote users are aware when a security problem occurs.