Going After the Little Guy

About once a month, the junk mail filter SpamButcher is updated. That doesn't always mean users need to upgrade. If users are only getting a few junk messages daily, upgrading may or may not help, and probably isn't worth their time. In some minor cases, the updates aren't even announced via a revised version number.

There have been a few changes over the last year in the methods used to modify and upgrade the code behind SpamButcher. For one, updates are a bit more frequent. This reflects that spammers are getting more aggressive in analyzing spam filter behavior and adapting to it. The problem is compounded by the availability of open-source spam filtering code. Open-source software, like many other technologies can be used for either good or evil.

One of the advertised benefits of using fuzzy logic is that it doesn't need as frequent updates. This is still true, but a drop in the email spam software's effectiveness from 98% to 96% results in a doubling in the amount of junk email users receive. This obviously results in a lower percentage of trial customers converting to paying users. At the end of the day, SpamButcher is a for-profit venture.

In the past, any additions to the filter needed to be of a general nature. That is, specific spam campaigns weren't targeted directly, as they would likely vanish at some point in the near future. Adding hundreds of specific phrases could result in bloated code, which slows the application down without offering anything to the user.

Further analysis resulted in the exact opposite conclusion. Research indicated that many email advertising campaigns linger on for a year or more. Sometimes different campaigns use the same email sending software, which can result in the signature phrases being present.

Frequent filter updates allow users to benefit from the new code, even if the specific format of messages targeted only persist for a few months. Now, specific internet spam campaigns are targeted for elimination. Again, the risk is that the code-base could become bloated, but that's mitigated by the increasing availability of processing power.

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