With more than a third of UK workers checking their inbox every 15 minutes, researchers from Glasgow and Paisley universities have found that employees are suffering 'email stress', leaving them tired, frustrated and unproductive.

When researchers fitted monitors to the computers of the 177 participants, some workers were found to be viewing emails up to 40 times an hour.

About 33 per cent of participants said they were stressed by the volume of email and, a further 28 per cent said they felt driven to respond as quickly as possible.

The remaining 38 per cent said they were comfortable to wait a day or longer before replying.

The survey was conducted by Karen Renaud, a computer scientist at Glasgow University, and Judith Ramsay, a psychologist at Paisley University.

"Email has become an indispensable tool in business. However, there is evidence that email can exert a powerful hold over its users and that many computer users experience stress as a result of email-related pressure," said Renaud.

"It's an amazing tool, but it's got out of hand. You want to know what's in there, especially if it's from a family member or friends, or your boss, so you break off what you are doing to read the email."

"The problem is that when you go back to what you were doing, you've lost your chain of thought and, of course, you are less productive.

The study found that females tended to feel a greater need to respond promptly.

Those working in creative positions such as writers, journalists, academics and architects were likely to be worst affected as that type of work typically requires longer periods of deep concentration.

"People's brains get tired from breaking off from something every few minutes to check emails. The more distracted you are by distractions, including email, then you are going to be more tired and less productive."

The report concluded that workers should avoid constantly monitoring their inbox, possibly even turning off the notification feature contained in most email programs, and instead setting aside dedicated email reading times to catch up on their messages.