In Kerio Connect, the filtering of personal mails is based on the filter language Sieve. As I didn't find many good samples in the Web, find below some interesting ones. I will update when I have new ones:
if allof (
header :contains "Subject" ["rma *","* rma","* rma *","rma"],
address :all :contains "Cc" "firstname.lastname@example.org")
This copies any mails to the folder RMA that match the following criteria: The subject of the mail contains the word RMA and the mail has email@example.com in the CC field. Words containing rma (like pharma) do not match.