Silicon Valley entrepeneur invents new spam trap

Recently he has taken on the challenge of e-mail spam. This year he founded Abaca, a company with a new approach in the crowded market for stopping junk electronic mail.

Abaca claims that it can filter out 99 percent of all spam, and supports the claim with a money-back guarantee. According to the result of an independent survey last February by Opus One, a computer industry consulting firm in Tucson, Ariz., that would be significantly better than the results of six leading spam blockers.

Abaca has taken on a new urgency for Mr. Kirsch — during the summer, he was discovered to have a rare form of blood cancer, Waldenstrom’s macroglobulinemia, that is found in about 1,500 Americans every year and is considered incurable, although it can be managed beyond the five- to seven-year longevity that new patients are usually told to expect.

So far he has shown no effects from the disease, and he said he is intent on applying his engineer’s approach to the problem.