90% of e-mails delivered to large companies in November 2007 were spam

Nearly 9 out of 10 email messages delivered to large enterprises in November 2007 were spam, according to Proofpoint. While overall spam levels dropped slightly (from 89% in October to 88% in November), large companies were still receiving an extremely high volume of spam, with an upsurge in attachment-based spam of almost every kind.

Image-based spam made up nearly 10% of all unsolicited emails delivered to enterprises in November 2007, up 24% from the previous month. About 5% of all spam came in the form of Microsoft Word (.doc) attachments, a 65% increase over from October 2007.