A BOOK which gives readers a masterclass on the rules of emailing has hit the top of the US bestseller list.

Send: The How, Why, When - and When Not - of Email made it into the top 10 of the New York Times bestseller list within 48 hours of hitting the bookshops.

The book, written by Will Schwalbe and David Shipley and published in Britain next month, contains helpful tips on how to avoid the pitfalls of the mis-sent message or the love note that didn't quite work. Other lessons on so-called `netiquette' the book dishes out are of a more moral tone - for instance, it says that an emailer should never mention anyone in an email who they would not be happy to show the content to.

Mr Schwalbe said: "It just takes one person to leak a careless email from inside a company for the whole firm to be dragged through the mud. And yet it might have been written by an employee who has only been there a week."

'Backlash'

A recent survey found that more than half of those questioned spent two hours a day looking at emails, while a quarter of those questioned had at least 200 messages in their inbox at any time because they have no time to clear them.

Mr Schwalbe said: "I am a moderate emailer and yet I probably deal with around 80 a day.

"That makes about 45,000 a year, so I understand why there is a backlash. But the truth is we are not going to stop using them."

According to a recent study, email overtook the telephone in the office three years ago, while research has found about one in every six people on the planet uses email, with about two million emails going out every second.