You may think nothing of them as you dash them out, but emails can come back to haunt you. Nick Morrison asks: when emails are concerned, is there such a thing as privacy?

WHEN Trevor Luxton wanted to boast of his sexual exploits, he was clearly looking for an audience. What he hadn't counted on was that audience stretching to several million. The banker sent an email detailing his encounter to colleagues, who then proceeded to forward it to colleagues, friends and anyone they could think of. Within hours, it had gone round the world, putting Luxton's job and his relationship with his fiancee - who was not the woman involved - at risk, not to mention his honour.

But Luxton isn't the only person to have been damned by electronic mail. Solicitor Bradley Chait was similarly compromised, when he forwarded an email from one of his sexual conquests praising his performance to six colleagues at his law firm. Spreading more quickly than a bush fire, it soon reached Australia, and Chait was disciplined by his law firm for bringing shame upon the company.

Less intimately, but no less shamefully, Jo Moore was forced to quit as a special advisor to Transport Secretary Stephen Byers, after an email suggesting the September 11 attacks provided an opportunity to "bury bad news".

Last month, a personal assistant at a financial advisors in Bristol was paid £10,000 in compensation after discovering she was the subject of obscene emails circulated by colleagues. There's no doubt that email has the potential to cause a lot of trouble.

But this may come as a surprise to even regular emailers. The speed and thoughtlessness with which many of us dash off our emails belies the far-reaching effect of an ill-judged word or a misdirected message. Few of us may be able to remember exactly what was said in every email, but that doesn't mean our words won't come back to haunt us. A key feature of the Hutton Inquiry into the death of Dr David Kelly has been the email trail among Government advisors over the preparation of the dossier on Iraq's weapons of mass destruction.

"Emails are inherently insecure and unreliable," says Quentin Campbell, systems programmer at Newcastle University and responsible for the university's electronic mail. "They are unreliable because of the nature of electronic matter: you can't guarantee the timeliness of the delivery, or that they will be delivered at all.

"And it is insecure, not because people can easily intercept an email, although it is easier to intercept than a telephone call, but it is insecure because of the nature of electronic mail systems. It is the danger that it doesn't get delivered to the person you want it delivered to."

Emails where the address has been written incorrectly, which are redirected, or have not been delivered for some other reason, may end up being read by someone other than the intended recipient. And, unlike a phone call, if you don't get through to the person you want, you don't necessarily know about it.

Any organisation which runs an email system will have a designated postmaster, and one of their jobs is to deal with misdirected mail. While any postmaster with integrity would bend over backwards not to pry into other people's emails, they do have the ability to do it.

Employees who wanted to keep their electronic communication private were given some protection by the Regulation of Investigatory Powers Act of 2000, which made it a criminal offence to unlawfully intercept an email. If the intercepting is done by the company which owns and operates the system, it may not be a criminal offence, but it can give rise to a civil action, unless the company has warned its staff that this could happen. An exception might be if the emails contain personal information, such as medical details or trade union activities.

But the added danger is that, unlike letters, it's much harder to destroy the evidence, according to Bill Goodwin, chief reporter at Computer Weekly magazine. "If you delete it from your system it doesn't disappear, it's still there and it's still recoverable," he says.

"Most workplaces have back-up systems and emails go through so many computer systems before they get to their destination, there will be a record."

But he says employees may have some recourse against companies which look at their private emails.

'If you mark an email 'personal', then an employer shouldn't really be looking into it. However, employers do need to monitor emails for a variety of reasons, including looking for viruses, checking you are not emailing confidential information to a rival, or saying libellous things about your customers, but they should only do this within certain limits.

"You can complain to the Information Commission and they will investigate and if your employer is invading your privacy they can be asked to stop. And if it causes you any damage or you lose your job because of something you have written in an email, you could have an industrial tribunal claim against your employer."

He says the best way to look at emails is to equate them to postcards: you should assume it will be read by everyone from the postman to the person who picks it up by mistake in the hall.

"I think people tend to treat them like a phone call, and they will say things in an email they wouldn't dream of putting in writing. Because it is very easy to send an email, people write all sorts of things, but that is where problems can arise.

"People can be quite rude about colleagues, or use language they would never use in a formal communication, but the rule is do not put anything in an email you would not put in a letter."

When it comes to the law, emails have the same force as a signed letter or a fax. That is, they can be just as incriminating. An exception is where they have been intercepted by Government agencies, when they are specifically prevented from being used as evidence in court.

"It is up to the court to decide whether or not they put much store in the veracity of an email," says Quentin Campbell. "It is easy to forge an email, as easy as it is to forge any other documentary evidence, but emails are not treated any differently from any other evidence."

Emails that have been stored - and all emails are stored on the server long after you've deleted your copy - can be seized by the police and used as evidence. As far as the courts are concerned, emails are just the same as any paper document stored in a filing cabinet.

In short, just because it's on an email, don't assume it's safe. Far from it. "It's more dangerous in some ways, because of the ease with which you send emails. They're easy, once received, to forward on to two or more people," says Mr Campbell.

"They're more dangerous than telephone calls, in that if people are careless in the way they use emails, they're more at risk. My practice is always to be very circumspect in what you say in an email. Always assume that it is going to end up in the wrong hands. You should say nothing in an email that you are going to feel uncomfortable about explaining." It seems as far as emails go, there's no such thing as privacy.