A couple of weeks ago I wrote about my worries, and my last worry was what malware might be lurking in our e-mail archives.

To recap: When I recently tested a new e-mail indexing tool, it opened messages and their attachments that I had filed away unopened or deleted but not purged. In the process, the indexer turned up a treasure trove of viruses and worms that for one reason or another my anti-virus system had not caught.

This led me to worry about the scale of this problem in the business world - these stock piles not only act as a pool of latent infection that periodically will be disturbed, cause problems and cost money, but their existence means that malware never will be eradicated completely. A big worry indeed. Well, I just heard of a bigger liability that lurks in your messaging systems: old message content.

I chaired a couple of sessions last week at the Inbox conference in San Jose, and one of the other sessions I attended was titled "The Email Comedy Club: Membership Details." The speakers were Joan Feldman, president of Computer Forensics, and Elizabeth Charnock, CEO of Cataphora.

These companies specialize in electronic discovery - the art and science of analyzing corporate data and e-mail for legal cases. What struck me first was the scale of the work they get involved in, compiling and processing terabytes of data and building up a picture of what was said, by whom, how it was said, what was not said and when these events happened.

But wow! The dumb things people put in e-mail. Charnock groups the dumb messages into categories, what she calls the "The Seven Ugly Dwarves": freaked out, angry, conspiratorial, confessional, friendly advice, personal and confused.

A few of Charnock's examples are worth citing, such as this freaked out message: "It is all hopeless. It can't be done. We have to let the client know we can't deliver on this contract. There are too many risks of defects." Charnock points out that this could be a tired, frustrated employee letting off steam, or it might be a whistle-blower indicating a real problem.

Or how about implied conspiratorial exchanges: 10:23 a.m., Joe to Jane: "The stock will be going up by at least 20% tomorrow. Don't tell anyone." Followed by 10:39 a.m., Jane to Jill: "Meet me in the cafeteria in 10 minutes."