The Security Mentor

If you have an email program that doesn't restrict incoming email to plain text, and if it doesn't have tight security controls, or if you open Office documents from email, then you can reveal more information than you expected.

A couple of companies sell a serivce where you can tell whether and where a recipient has opened or forwarded your email. The software that makes it happen can lurk in the deails of a web-formatted email message, or inside an attached Office document.

Well, I could talk about ways to prevent the tracking, but let's be real. You can't do business without accepting attached Office documents. I don't know any antivirus that will detect the tracking features, which are often just a surprising and creative abuse of some perfectly legitimate feature of Office.

Closest thing to a solution is to block HTML email or at least (for Microsoft users) make sure it's running in the Restricted Sites zone, and then run a product like Zone Alarm that will alert you if Microsoft Word suddenly begins trying to talk to strangers over the network.