The research, led by management professor Russell Johnson and published in Journal of Applied Psychology, is one of the first to examine how distractions from email impact managers, their productivity and their role as leaders.

According to the research, employees spend more than 90 minutes every day -- or seven-and-a-half hours every week -- recovering from email interruptions. Managers, Johnson said, are no different, and their distractions have further-reaching implications.

"Like most tools, email is useful but it can become disruptive and even damaging if used excessively or inappropriately," Johnson said. "When managers are the ones trying to recover from email interruptions, they fail to meet their goals, they neglect manager-responsibilities and their subordinates don't have the leadership behavior they need to thrive."

What further makes managers different from other employees is that when feeling overwhelmed and unproductive because of email demands, they recover by limiting leader behaviors and pivoting to tactical duties. This action, Johnson said, is strategic and intentional so that they feel more productive.

"Interestingly, we found that managers scaled back 'leader behaviors' more so than initiating 'structure behaviors,'" Johnson said. "The former behaviors relate to motivating and inspiring subordinates, talking optimistically about the future or explaining why work tasks are important; the latter are more concrete and task-focused, such as setting work goals, assigning duties or providing feedback."

So, not only are managers not managing -- but they're also focusing on smaller tasks for the sake of feeling productive.

To test how email demands hinder managers, Johnson and colleagues collected surveys from a group twice a day for two weeks. Managers reported their frequency and demands of emails, their perceived progress on core job duties, how often they engaged in effective transformational leader behaviors and initiating structure leader behaviors.

"We found that on days when managers reported high email demands, they report lower perceived work progress as a result, and in turn engage in fewer effective leader behaviors," Johnson said.

Beyond failing to complete their own responsibilities, email distractions cause subordinates to suffer from a lack of leader behaviors, or those that motivate and inspire.

"When managers reduce their leader behavior and structure behaviors, it has been shown that employees' task performance, work satisfaction, organizational commitment, intrinsic motivation and engagement all decrease, and employees' stress and negative emotions increase," Johnson said.

Importantly, Johnson said, leader behavior has a strong correlation to employee performance which, unfortunately, were the behaviors that got put on the back burner because of email distractions.

"The moral of the story is that managers need to set aside specific times to check email. This puts the manager in control -- rather than reacting whenever a new message appears in the inbox, which wrestles control away from the manager," Johnson said. "As we cite in the paper, findings from prior research suggest that it takes time and effort for employees to transition between email and work tasks, so minimizing the number of times they have to make that transition is to their benefit."