Postini and other similar email filters do the job of filtering ingress and egress. Ingress is simple enough - tossing as much spam and unsolicited garbage in the bit bucket before it clogs up up your servers hard drives. And, doing some level of malware filtering to drop as much email born malware as possible. Does that require reading the content? At a bit level and perhaps code script level it does yes. For egress filtering it also does some of the job of firewalls to prevent outbound redirects through the mail to prevent reinfecting yourself or others outside of your campus lan. But as far as scrutinizing content and such - that's a reach. Beyond the coarse grained level of removing bitmaps, attachments embedded urls there's not much humanly possible. Since no one has a way to efficiently tag embedded content with an external flag or wrapper that creates a security taxonomy there's no way to block sending out those marketing plans on PDF, really. Oh in theory but it's not worth the cost.

I think the real complaint in the article is about another product altogether; one that does URL filtering. Which prvents access to and from specific domains.

Farhad you are right, the only reason for controlling end-user activity is because that’s the way “The Man” wants it. It has nothing to do with keeping machines and networks clean so the company can continue to function and therefore bring in revenue. And it has nothing to do with the fact that things like IM and email are a huge conduits for malware and viruses, and that some companies are required to archive all correspondences for regulatory reasons and that some companies have important data and or trade secrets that need to be protected from people that think it’s ok to violate common sense and corporate policy with comments like “what could happen” or “why would anyone be looking for my data”, Or the ever popular, “ The company screwed me so I will take the data with me when I start my job at a competitors” , or “when authors over-sensationalize articles titles and content because they need to put a “Spin” on it to make it better. Oh wait, I’m sorry that last line should be in the next paragraph. Right next to, "grow up" and "I am sure Google may do bad things, but if you’re going to point fingers at them, at least bring something valid to the table when you do".