Your sentence is a bit broken up - but if you are asking how to block hotspots - you really can't. There is nothing you can do from a technology standpoint with the exception of wrapping your building in tinfoil to block someone from using their own hotspot or phone as a hotspot.
Verified VPN? Gonna have to explain that one to me as well.
If you are trying to block traffic on YOUR network, looking at the Kerio website i see VPN specific features, but i'm not seeing anything on their website (i only glanced) that says web filtering. There are dozens of other applications that can do web and content filtering on YOUR network if desired.