The free ZoneAlarm is no longer a stand alone installer. When you download ZAFree you are actually getting the installer for ZAISS. You actually install ZAISS, but when you start ZA and it asks you do you want to try the ZAISS version for 15 days for free, and you turn it down, then when ZA starts up all you see is the free version.
Mailfrontier is the spam filter used in ZAISS