getting ***UNCHECKED*** in subjects of received emails

[Nikolai Maziashvili]

Hi everyone, i'm running fresh KOLAB33 on CentoOS7 machine and getting 
***UNCHECKED*** in subjects of received emails. I assumed that clamav db 
was out of date and tried to refresh it by running freshclam, but to my 
surprise it was not on the system???
Clamav is not the one responsible for spam checking? Or should i install 
it manually (provided by clamav-update)? And if yes, should i keep 
anything specific in my mind, regarding kolab, when editing freshclam 
config file?
Thanks in advance,
Nikolai