The secret to happiness is to turn off your smartphone e-mail app, according to UK psychologists, who warn that constant updates have become a "toxic source of stress". E-mail pressure was highest among younger people and steadily decreased with age, according to the findings presented at the annual meeting of the British Psychological Society's Division of Occupational Psychology. Those working in IT, marketing, public relations, the internet and media were most affected.Experts in digital distraction and productivity suggest managing this stress by limiting how often the app is checked, setting "out of office" replies and recognising that, if a matter is urgent, employers will probably call. ..