Definition of FALSE-NEGATIVES
The false-negative rate is the percentage of spam interpreted by antispam as legitimate e-mail. A solution like ALTOSPAM, which blocks over 99% of spam, has a false-negative rate of less than 1%.
ALTOSPAM blocks spam with a filtering rate between 99% and 99.2%, so the service generates a false-negative rate of 0.8%. We consider it preferable to receive the occasional spam message, even though ALTOSPAM’s filtering rate is more than respectable, rather than block legitimate e-mails and generate false positives.