"She's sleeping with her boss and his wife doesn't even know!"

"It's just not working out ... I think we should break up."

"I just heard he's going to be fired tomorrow — but don't tell anyone."

Firing off personal e-mail (search) messages such as these to friends, family and co-workers is standard practice among many — in spite of wide reports that the medium is not necessarily private.

And these days, it's not just crooked CEOs having their e-mails trolled. A recent ruling by the First Circuit Court of Appeals (search) found that if an Internet Service Provider (search) copies and reads your e-mail for commercial gain, it is not breaking federal wiretap laws (search).

But still, many people take about as much time to consider what to write in an e-mail as it takes to send it.

"I still send rather personal information to individuals without any fear," said Lauren Friedman, a senior at Stanford University. "After all, the worst that can happen is someone else reads my love confession or really embarrassing moment. They'll know a bit about my personal life, but I won't get in any legal sort of quandary."

But even a sweet love note could breach a workplace's e-mail policy.

"E-mail is certainly a part of our lives," said Jacqueline Whitmore, founder of The Protocol School of Palm Beach, which offers business etiquette classes. "I don’t think you should be sending personal messages on the company computer — you should save those for when you get home."

Whitmore added that there are some exceptions.

"There is a difference between sending office gossip and sending a few lines that is personal but not harmful."

Whitmore said people might know that it's possible for others to read their e-mail, but they don't believe it will ever happen to them.

"If they do anything suspicious, that is one way the company can check out their reputation. They need to be extremely careful," she warned.

But with so many people getting away with it, it's no wonder that many employees don't feel e-mail fear, Whitmore said, offering an example from a previous job.

"One of the men — he was on the management committee — was sending pornographic pictures throughout the company and sent it to the wrong list of people, which included two women. These women got terribly offended and he got called in by the president and basically just got his wrist slapped and is still with the company. I would suspect to this day he still does it."

Pam Small of Falls Church, Va., may be an exception to the rule — she's tempered her e-mailing to protect her privacy.

Small said it's clear to her that "e-mail sent through my company computer is not private — it doesn't belong to me and should be respected as the property of the company.

"On the Internet, nothing private is private. And anything that you wouldn't want to see on the front page of The New York Times should never be sent. Not to mention that e-mail is discoverable evidence — so why play with fire if you don't have to?"

Friedman said for the generation raised on keyboards, e-mailing is second nature.

"It's a normal part of life, like slipping notes to each other in class. People don't understand how it's different."

The proliferation of e-mailing could be a gold mine for marketers, who could potentially use messages to profile users.

Under the First Circuit Court of Appeals' decision, "any node on the Internet that passes e-mails could flip a switch and start looking at any e-mail that passed through it," Kevin Bankston, a lawyer at the Electronic Frontier Foundation, told the Wall Street Journal.

Be sure to check your e-mail provider's privacy policy to find out if they are scanning your messages, and if so, for what purposes and how often.

As for rulings and studies suggesting e-mail is not private, Friedman said: "I really don't think anyone pays attention to that stuff, not only because we are so used to it, [but because] it's hard to change how you already perceive something. If someone were to tell me that about my cell phone, it would be very hard to change it. It's hard to break that habit."

But some have been forced to. Friedman said many of her friends are currently doing summer internships in offices where Web mail such as Yahoo is not accessible on company computers — a restriction she thinks will backfire.

"I know that the intention is good to limit personal communications at work — but I think it's actually going to encourage them to use their work e-mail accounts for play," she said.