Emails are a 'double-edged sword' that provide a useful means of communication but can also be a source of stress, according to research by psychologists.

Constant email updates are a source of stress that people should consider doing without, according to a report by psychologists.

A key recommendation is not having the email app running at all times - something many users would regard as heresy.

The report is from the London-based Future Work Centre, which conducts psychological research on people's workplace experiences.

Urging users to seize control of their email instead of being ruled by it, the authors said: "You may want to consider launching your email application when you want to use email and closing it down for periods when you don't wish to be interrupted by incoming emails.

"In other words, use email when you intend to, not just because it's always running in the background."

The team surveyed almost 2000 working people across a range of industries and occupations in the UK about using email.

They found that two of the most stressful habits were leaving email on all day and checking emails early in the morning and late at night.

Higher email pressure was associated with more examples of work having a negative effect on home life, and home life having a negative impact on performance at work.

Lead author Dr Richard MacKinnon said: "Our research shows that email is a double-edged sword. Whilst it can be a valuable communication tool, it's clear that it's a source of stress or frustration for many of us.

"The people who reported it being most useful to them also reported the highest levels of email pressure. But the habits we develop, the emotional reactions we have to messages and the unwritten organisational etiquette around email, combine into a toxic source of stress which could be negatively impacting our productivity and wellbeing."

Email pressure was highest among younger people and steadily decreased with age, according to the findings presented at the British Psychological Society's Division of Occupational Psychology annual meeting in Nottingham.

In 2014, an estimated 196.3 billion emails were sent around the world, according to the report.