How to Filter with Finesse

"Earlier this year, a company called Pivotal Veracity published a 33-page study on the prevalence of false positives in antispam systems operated by three of the largest Web mail providers. Pivotal Veracity is itself an e-mail consulting service (more on it later), which might have led some people to dismiss the research. But the company's methodology was very good and the results were interesting and important. To conduct its study, the researchers at Pivotal created Web mail accounts at Google, Microsoft and Yahoo. They then signed up for e-mail newsletters from 100 randomly chosen corporations, nonprofits and governmental agencies. Then, over the next six weeks, the researchers checked the mailboxes to see if mail from those senders got delivered to the inbox or the spam box." Source: csoonline.com