Accuracy and False Positives

• The big issue with filtering to date:

  • not just “how much spam does it catch?”
  • but “how many legitimate mails get caught, too?”

• Many systems do not pay attention to this problem

  • Some blacklists even use "false positives" as a weapon against service providers selling to spammers

• FPs are much worse than spam getting through

  • much more inconvenient to user