So last year Lynn sold the firm and joined a financial services company. When he negotiated his contract there was one condition. "I made the head of human resources agree that I would not have to deal with more than 25 e-mails a day. He looked at me as if I was asking to have one of my hands tied behind my back but, looking back, it was one of the best moves I've ever made."

For most office workers joining the "25 e-mails or fewer" elite is a distant dream. In the five years since it became commonplace in homes and offices, e-mail has gone from being the fastest-growing new communications technology to the bane of our working lives.

We work, trade, flirt and generally waste more time online than any other way. `Bing-Bong! Do you want to go the cinema tonight? Bing-Bong! Don't forget it's your father's birthday next week. Bing-Bong! Your account is overdrawn. Bing-Bong! Fancy a fag? Bing-Bong! Erica's had a baby and here - click on the attachment - is the first picture of her. Bing-Bong! Save dollars on life insurance. Bing-Bong! You must see this!!!!!!!! Bing-Bong!

"Where's that report I asked for yesterday? It's already late." Many of us spend so much time on e-mail that there's hardly time for work. It was not supposed to be this way. By promoting fast, cheap communication, email - we were promised - would free us from the tyranny of the office, letting us work wherever, however and whenever we wanted. By speeding up the boring bits with a keystroke here and a click there, productivity would rise, keeping bosses happy, while freeing up more time for the rest of us to speak face-to-face, talk on the phone and go home earlier.

As if every night workers stay late answering mails. Many come back the next morning only to do the same over and over again. The average office worker spends about three hours a day sending and receiving some 150 electronic messages. Figures from British Telecom show that last year - for the first time - the amount of data we sent each other through e-mail exceeded voice traffic. We e-mail more than we talk.

The more text we send, the more we are falling victim to what the psychologist David Lewis calls `information fatigue syndrome'. Symptoms include exhaustion, anxiety, memory loss and short attention span in the face of the uncontrollable onrush of facts. `Having too much information can be as dangerous as having too little,' Lewis says.

How have we all become such stressed-out anoraks? E-mail has fallen victim to the law of diminishing returns that seems to blight virtually every so-called technological breakthrough from the PC to the mobile phone.

The faster we can work, the more we can do - the more we end up doing. Bosses ask for more - because it's easier than ever to ask. Count up the bullying memos and see for yourself. Family and friends want more attention and can track you down wherever you may be. "What do you mean you haven't looked at our holiday photos? They took ages to scan in and we sent them two days ago." Advertisers know we're online and bombard us with promotions. "Sign up today and receive 10 per cent off your first bill." Great technology, but what's the net gain? Zilch.

Some researchers warn that we have become such slaves to our machines that we are turning into socially inept loners. Helen Petrie, professor ofhuman-computer interaction at London's City University, says: "We have lesstime and suffer more stress than ever. Many of us are moving from a world in which we knew our neighbours, friends, and colleagues into a virtual world where interaction is distant.' But there are signs of a backlash.

Studies by the UK's Consumers' Association show that the number of persons who say e-mail is their favourite form of communication has plummeted in the

past 12 months. The number who prefers face-to-face meetings is rising sharply. Some of Britain's biggest firms including Thomson, Rowntree Nestle

and Camelot, are introducing `e-mail-free Fridays' to encourage staff to talk to each other.

Others are introducing strict codes of conduct to curb copying of irrelevant memos to colleagues, cut down the number of links to `comedy'

Websites clogging up company servers and help workers manage their inboxes.

Some have hired "e-assistants' to filter key executives" e-mails. Manufacturers are developing software that allows users to reject e-mail from named senders, automatically file others and search for key words to rank messages in order of importance. Alison Spottiswoode, senior e-business executive at IBM, says: "We want to help firms use the technology, not be used by it. We tell our own staff email is just one way they should communicate."

Thirty years after scientists working for the US military sent the first e-mail, the technology is revolutionising the way we live. We cannot log off but we can log on less.