You can additionally purchase an Anti-virus Extension for $2.30 per user, per year and/or a Web Filter Extension for $4.80 per user, per year.
Anti-virus extension checks incoming files for viruses and malware
Web filter extension enables customers to block web sites or web site categories
GFI KerioControl available as a Hardware Appliance
Purchase GFI KerioControl as hardware with no limit on users, or as hardware with software licenses priced as above.
When purchasing a subscription with no user limits, GFI does not restrict the number of users or devices connected to the appliance; customers have to set their operational limits to ensure they don’t overload the appliance. The yearly price includes the anti-virus and web filter extensions.