This special is only good until the end of today (11/25/17).
If you have email without good spam filtering then you'll want this. I've been using Cloudmark Desktopone for my email antispam, but that goes away December 1st. So far this seems to be the best replacement.
The catch is this will auto-renew after a year at the full price, so be sure to cancel auto-renewal before then. The renewal price is $29.95.