> "Interestingly, the majority of energy usage (around 80%) comes from
users viewing and deleting spam, and searching for legitimate emails within spam filters."
Right -- if your users can't trust their 'spam' folder as spam, then what is the point? They should keep it around so they can check it in case they seem to be missing a message, but generally speaking, you should get few enough false positives so that the risk of false positive for each user is nearly zero. Then the spam folder is actually useful.
This does mean, however, that you can't assign very high value to some of the rules that can often yield false positives such as the BOTNET rule which assumes everyone has proper rDNS, etc.
Best, Jesse
