Spam filtering review and compare

02.Results

If you use Outlook Express you need an add-on spam filter and Popfile topped our list for performance, and supports a wide range of other email clients as well. Bullguard Spamfilter was also easy to use and effective. The default clients for Mac and Ubuntu Linux, Mac Mail and Evolution, did an excellent job as did Thunderbird, which has the advantage of having free versions for Mac, Linux and Windows.

What we found

Getting a spam filter set up to work properly is important or you’ll never get the most out of it. Unfortunately, the easiest to set up and use are not always the best performers. We looked at how easy each program was to set up and use, as well as how well it stopped spam.

Ease of setup

Of all the programs tested, the email clients Evolution, Mac Mail and Windows Mail were the easiest to set up because there was no need to download and install a separate program. Each of them was installed as part of their respective operating system and spam detection and filtering was enabled by default.

MailWasher Free scored a 90 (excellent) for ease of setup as it was easy to install and configured itself to work with the email client. Spamihilator and Thunderbird scored an 80 (very good). They were both easy to install, although Spamihilator required a reboot and Thunderbird required manual configuration of the email client.

Bullguard Spamfilter and SPAMfighter Standard were both scored at 70 (good) because although relatively simple to set up, they required a registration email address. The remaining filters all scored 60 (OK) primarily because although the installation was easy they required manually making spam rule and folder changes to the email client.

Ease of use

For ease of setting up and subsequent filtering of emails, Bullguard Spamfilter, Spamihilator, Evolution and Mac Mail were all rated as excellent.

It should be noted that although MailWasher Free, SPAMfighter Standard and SpamPal also scored highly for ease of use, partly because there was less for the user to do, as they were not trainable. This is not necessarily a good thing, as it ultimately results in less performance.

Popfile and SpamBayes scored a ranking of good for ease of use because although the training process was relatively straightforward, they had to be trained one email at a time. The programs don’t allow you to select a group of emails and classify them as spam with a single click.

Windows Mail also scored a ranking of good (70) for ease of use because of its simple spam level setting. Thunderbird scored even lower, with a rating of OK (60) because although easy to use, accidentally clicking on the program during the filtering would abort the process, which could be a problem if having to filter a large amount of email at a time.

Performance

Once trained, most filters were very good at letting legitimate messages through and not mistakenly blocking them as spam. The notable exception being MailWasher Free which scored very poorly in this test. See How we tested — False positive errors. All the others scored a 100 except for SpamPal with a 98, Windows Mail an 86 and Spamihilator a 71. Results for spam blocking varied much more, with scores from 22 to 100. Note that our testing was done using the default settings of each program as much as possible. Tweaking individual settings could achieve a better result.

Thunderbird scored the best result for spam blocking, with a score of 100, followed by Popfile with a score of 98 and Mac Mail with 93, all in the excellent range. In the very good range of scores for spam blocking were Evolution with 82 and Windows Mail with 80. Bullguard Spamfilter was just in the ‘good’ range next with a score of 73. The last four filters ranged from 52 down to 22.

The Overall score takes into account spam blocked, legitimate email not blocked, and the ease of setup and use. Four programs we tested were rated as excellent, with a score over 90. Top of the list was email client Mac Mail with 96, followed by the best-placed of the add-on programs Popfile on 93. Next were the open-source cross-platform email client Thunderbird (92) and the Linux email client Evolution (91).

Add-on program Bullguard Spamfilter was ranked very good overall with 84, as was Windows Mail with 81. Lowest scored overall was MailWasher Free (52), because even though it scored well in blocking spam, it also wrongly blocked a large amount of legitimate email.