Researchers have carried out a study and found that e-mails have gone from being a useful office tool to a curse that actually takes up huge amounts of work time, The Daily Telegraph reported on Monday.

According to the researchers, the average employee now spends an estimated 90 minutes to two hours a day wading through hundreds of messages, much of which is basically spam and junk mail.

The study by the Radicati Group has found that worldwide email traffic has hit 196 billion messages a day. It is predicted to reach 374 billion per day by 2011.

"Employees're now so deluged with messages that emails have become a broken business tool in urgent need of fixing. There's been no innovation to separate the junk letters from the real ones," Jason Preston of the Parnassus Group, a social media consultancy, was quoted as saying.

A related study by another research firm Telewest Business recently found that emails and telephone habits could reduce productivity rather than increase it and "men are the biggest timewasters at work".

According to the research, the misuse of telephones and emails at work was hindering office workers from doing their jobs, increasing bad habits at work and lengthening the working day.