In terms of everyday operation, Spamfighter Pro is almost indistinguishable from our Silver Award winner Cloudmark. Both add Block and Unblock buttons to your email program's toolbar (compatible with Outlook, Outlook Express, Windows Mail and Thunderbird) and both rely to some extent on the user community to accurately flag and filter spam. Both are also good at what they do, collectively having blocked 50 billion spam messages according to the live statistics collated by each application.

Spamfighter Pro is marginally cheaper than Cloudmark and also provides a slightly better level of control over the sensitivity of the filter (five levels are on offer, from ‘very soft' to ‘very hard').

The main distinction between the two products is in their black- and white-listing abilities. Email addresses (or domains) in a blacklist will always be classified as spam while those on the white-list will always be allowed through. So what's the difference? Well, Cloudmark doesn't have a local blacklisting facility as such - only white-listing. In other words, Cloudmark users have to rely on Cloudmark's blacklist, while those protected by Spamfighter Pro can augment the community blacklist with local exceptions.