Here's a copy from the site of the real benefits of Nucem in reply to Real's question.
What is unique about NUCEM when compared to other anti-spamming solutions?
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Currently, first generation anti-spamming technologies are reactive solutions, which attempt to manage the spam received. The vast majority of anti-spamming solutions are filter based, which do nothing to stem the flood of spam, nor do they attempt to prohibit the spammer from sending spam in the first place. First generation anti-spamming technologies do not scale very well.
Spammers and filter providers continue to leapfrog each others technologies, where the spammer uses technology to overcome the latest filter technology, and the filter provider adds more filter rules to identify the latest spammer techniques. As the filter provider adds more rules, they require more processing power as they are required to evaluate all rules for each e-mail message received. In some cases, valid e-mail is mistakenly identified as spam (false positive), and this can be disastrous for individuals and corporations.
Additionally, filter technology cannot be customized to each person's preferences, so what is spam to one person must be spam to every person. What is spam to one person may not be spam to another. For example, one e-mail user may have subscribed to a newsletter, and this newsletter may contain phrases normally identified by filters as spam, and hence the e-mail user will be prohibited from receiving the newsletter they might have paid for.
Filter technology cannot process images, HTML, JavaScript, or any other scripting language. Therefore, most companies who employ filter technology will also block any e-mail that is not plain text. This includes all e-mail attachments, images, JavaScript, etc. Therefore, e-mail becomes no more useful that the old teletyper.
The real problem with filter based solutions is that they are analogous to paying protection money, so the e-mail user does not have to see the spam they are receiving. Filters do nothing to help the e-mail user when they send e-mail. Their e-mail will still be swamped by spam in the inbox of the recipient they are attempting to correspond with. Furthermore, filters do nothing to help fellow net citizens from the abuse of spammers located all over the world.
NUCEM is the first of the second generation anti-spamming technologies, which stops spammers from sending spam, or said another way, NUCEM stops spam at its source. The philosophy behind second generation anti-spamming technology has nothing to do with stopping spam from reaching its recipient; it is only interested in ensuring that it is not sent at all.