As the spam problem grows, so does investment in anti-spam vendors, not to mention the number of anti-spam vendors. Last week, former Netscape Communications Inc. chief technology officer Eric Hahn launched Proofpoint Inc., backed by $7 million in first-round funding from Mohr, Davidow Ventures, Benchmark Capital, and Stanford University. Hahn is touting Proofpoint's combination of machine learning and statistical analysis as able to go beyond detecting what's already known to be spam to catch "E-mail spoofs" that appear to be sent from legitimate addresses. The same day, IronPort Systems Inc., founded by former Hotmail exec Scott Weiss, received $15 million in second-round funding, led by Menlo Ventures, and Cloudmark revealed a $4.5 million infusion from Ignition Partners. IronPort and Cloudmark launched their anti-spam offerings last year.