I've never used Kerio but I had read some good things here about it especially that it didn't use too many resources. A friend asked for a very light firewall and I told her about Kerio. She downloaded it and said that AdAware said that it contained Ezula as well as other stuff that "hid" itself even after she tried to remove Kerio. She removed Kerio due to the spyware issue. Any truth to this from you Kerio users? Thanks.