AS THE ART OF LETTER WRITING GOES the way of the 32 cents stamp, more and more of what pops up in our mailboxes at home is nothing but garbage. So is it asking too much to want our E-mail boxes, especially those at work, to be junk-free?

Don't count on it. A Mar. 29 study from Internet security consultant Worldtalk Corp. says that almost one-third, or 31%, of corporate E-mail is junk. And unlike the innocuous supermarket sales fliers that jam up the mail slot at home, this junk mail is causing financial loss and service interruption. "Internet E-mail abuse is worse than we expected," says Simon Khalaf, who oversaw the study at Worldtalk, based in Santa Clara, Calif. The study was compiled from network surveillance of more than 31 million messages in systems worldwide.

Other findings: Employees spend, on average, 30 minutes a day sifting through their deluge of E-mail. Spam-mail--unsolicited messages from unknown senders--can cost a 5,000-person organization more than $12,000 per day to process. That's 50 cents per employee, to check and delete junk-mail messages.

And incidents of E-mail leaks aren't all that uncommon. According to the study, some 9% of all corporate E-mail messages include some form of proprietary or confidential information, such as product plans, and are sent out maliciously or without the company's permission. More and more, "you've got mail" is likely to mean you've got a problem.

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