Think your work e-mail is private? Think again.

A recent decision by the National Labor Relations Board allows companies to restrict the use of their e-mail systems for union activities by their employees. The case dates back to 2000, at which time a union official for the Register-Guard newspaper in Eugene, Oregon, sent three union-related messages. The NLRB found that since the newspaper had a policy in place that restricted use of e-mail for "non-job-related solicitations" for outside organizations, it was within its rights to ban such messages.

What a surprise!

If your work entails use of your employer's e-mail system--whether or not the company has published an official policy on use of the system by its workers--you better assume that your bosses have the right to monitor your incoming and outgoing messages, and restrict use of the systems for purposes not directly related to your job.

I've been poking around the Internet trying to find a definitive answer to the question of e-mail privacy in the workplace, and it appears that there is none. The Privacy Rights Clearinghouse includes e-mail along with telephone conversations and computer use as workplace technologies that can be monitored by employers.

If you want to stay on the right side of your organization's e-mail policy, the first thing you have to do is find out what it is. If your employer hasn't published such a policy and made it available to you, ask them to formalize the matter. Next, no matter what the stated policy, assume you have no right to use your work e-mail for non-work purposes. Even signing up for an account at Gmail, Yahoo Mail, or some other Web mail system won't protect you because the PC and Internet link you'll use to access the mail will likely be owned by your employer.

So when your brother-in-law sends the latest list of Darwin Award winners or dumb-blonde jokes to your work e-mail address, reply by asking him to send future vital correspondences to your personal e-mail account, and get your giggle on in the privacy of your own home. Your home is still private, right?

Monday: Diagnose and repair the most common Windows glitches.