I like that it's easy to use, has many options for customization/tweaking (even if you're not tech-savvy), is very effective in blocking phishes from reaching your end users' inboxes! The interface could be more intuitive - some of its features are hidden behind complex menus or submenus which can make them difficult to find at first glance; however this may just take time getting used too so don't give up after only trying once as there might still be things about STOPhish we haven’s figured out yet :) We've been able block over 90%+ spam emails with zero complaints since implementing our own solution using Safe To Open Anti Spam service.