So much for the paperless office. Like a stack of paperwork rising to the sky, the infinitely expandable email inbox has become a cause of work-related anxiety for many employees.

According to a study recently published by Stine Grodal, an assistant professor of strategy and innovation in the School of Management, email is both a significant source and symbol of workplace stress. “It’s very visible,” she says. “You can actually see it on the screen, it has material properties. And so email becomes your to-do list of the day.”

Grodal’s interest in this phenomenon stems from her larger research on how communication technology impacts the amount of stress that workers experience on the job and at home, as well as their ability to cope with it. Together with study coauthors Stephen Barley and Debra Meyerson of Stanford University, Grodal—who has a background in psychology and engineering—is exploring how email is dissolving the (healthy) boundaries between work life and, well, life.

“People would tell us many stories and be very emotionally engaged whenever they talked about email.” Stine Grodal

The study aimed to assess how professionals in three different high-tech environments use communications technology. Participants—who included engineers, technical writers, and marketers, and whose proficiency with high-tech communications was assessed beforehand to ensure that learning curves wouldn’t skew the data—were asked to keep logs of all communication events they experienced during a series of workdays, including phone calls, emails, and face-to-face conversations. When Grodal interviewed participants afterwards about the stress these communications generated, she says, “90 percent of what people talked about was email.” Regardless of participants’ age and gender, email-related stress came out at the top of the heap.

“If you talked to them about phone calls or meetings, you would get very little information,” Grodal says. “There was not any kind of emotional response around that, whereas people would tell us many stories and be very emotionally engaged whenever they talked about email.”

Some of the stress and negative emotions surrounding email apparently stem from the idea, voiced by several study participants, that emails should be answered within an hour. Indeed, when Grodal and her colleagues reviewed the logbooks, they discovered that those interviewees who were most emotional in their responses about email-related stress were also the employees whose workday was most occupied by meetings and teleconferences.

“After the meeting,” says Grodal, “they come back to their office and log in to their computer, and they see all the email that has been piling up during the meeting.” It can be a daunting sight.

Another belief prevalent among participants displaying the greatest levels of stress was the idea that their email was piling up all night. It distracted them at home, and in the morning before they got to the office. “This triggers people’s checking behavior,” Grodal says. “They constantly have this voice in their head that says, ‘Maybe something has come into my inbox.’”

Because stress can lead to workplace burnout and turnover, costing companies time and money as well as human resources, Grodal encourages managers to “think about the norms around email use, and to have a clear conversation with employees about what is expected and what is not expected.”

Other suggestions for bosses include exempting employees from replying to work emails outside of business hours, or giving them a designated hour each morning to catch up on messages. In a team-project setting, one worker per day could be designated to handle the project’s email communication.

Next, says Grodal, “We need to go back into the field and test some of these ideas, to see what the drawbacks are and how people would react to such a restructuring.”