Years ago, if you were ticked off at somebody, you may have written him a nasty letter and put it in a drawer for a day or so until the anger subsided. In many cases, you'd then pull out the letter and throw it away, glad that you never mailed it. That response has saved many jobs and friendships.

Today we're in a different world, where the ease of e-mail has made some senders believe their correspondence is private. Unfortunately, the information contained in some e-mails has led to court battles and ruined business and personal relationships.

A recent article in the Boston Globe confirmed this when two lawyers (of all people) got into a nasty e-mail exchange over a rebuffed job offer. These "private" e-mails eventually were forwarded to several hundred people around the world, making the correspondence public information and a front-page article.

The article quoted Boston Bar Assn. president-elect Jack Cinqugrana as saying: "The dangers created by this new world we live in, where everything is recorded for history, are not only that you could be second guessed at every stage in the context of a civil dispute or government investigation, [but that] your reputation can be affected by words you don't think you're preserving for posterity—but really are."

He's right. Take a look at some of the cases involving some of the nation's largest corporations. E-mails have become some of the most important pieces of evidence in civil (and criminal) actions. Much of the evidence surrounding corruption cases involving CEOs at some major corporations is based on e-mails they sent to colleagues. E-mails create a paper trail that can and will be used against you.

E-mailing is still a relatively new method of communication. And it's easy to make a mistake when sending one. Maybe you just clicked on the wrong name, or hit reply to all rather than just reply, or sent an e-mail to the wrong "personal" group. This happened recently at one company, and 2,000 employees received an e-mail they shouldn't have received. Or maybe a friend has forwarded information about their company to you, believing the correspondence is just between the two of you.

E-mail is an important business tool. Used indiscriminately, however, it can cause you and/or your employees problems that could linger for some time.

jkeough@reedbusiness.com