It's hard to imagine how we functioned before email, especially in the business world. Over 200 billion email messages are sent and received every day. Email occupies 23 percent of the average employee's workday, and that average employee checks his or her email 36 times an hour. We feel so productive when we clear out our inbox.

However, a growing number of corporate leaders across the globe are discovering that limiting or even banning employees' access to email actually increases their productivity. In my new book, Under New Management, I profile many of these companies and also cover a number of different studies conducted recently support assertions that email isn't the best tool for staying productive and stress-free.

One research study even supports the idea of a moratorium on internal email. Researchers from the University of California at Irvine and the US Army cut off email usage for thirteen civilian information workers and measured the effects of the cutoff in a variety of ways. The researchers first took participants through a three-day baseline period in which they were interviewed and observed visually and using computer monitoring software. They even measured the participants' heart rates (as a proxy for stress levels). Then they pulled the plug on email, installing a filter on the participants' email program which would file away all incoming messages for later reading and remove all notifications.

This 'no-email' condition continued for five days, during which time the researchers continued to observe the participants, track their computer usage, and measure their heart rates. With no access to email, participants changed their habits: they began to communicate face-to-face and over the telephone more frequently. The researchers also noticed that all except one participant spent significantly more time in each computer program; this observation suggests that participants were more focused on the tasks in front of them and less distracted by attempts to multitask email communication alongside their intended work project. They also experienced significantly less stress during the no-email period than measured during the baseline. In short, participants were more focused and less stressed when they couldn't use email. Participants noticed this effect as well. They consistently reported feeling more relaxed and focused, as well as more productive, with their email shut off than under normal working conditions.

The productivity finding is particularly interesting: we often feel more productive once we've cleaned out our email inbox, despite perhaps not accomplishing anything value-creating for our organization. These researchers' findings certainly suggest that a zero-email policy could have a positive effect on a company's productivity and profitability.

While some leaders are suggesting a ban on email, some research suggests that limiting email checks to certain times may be just as effective as banning it entirely. A policy of moderation might be enough to bring about the same decreases in stress and increases in productivity.

Researchers from the University of British Columbia conducted a two-week-long experiment in which individuals toggled between checking email at will and restricting the number of times they checked it. Participants reported significantly less stress under limited-email conditions than under unlimited-email conditions.

Whether or not companies decide to restrict email, limit how often employees check it, or ban it entirely, both the research and recent experiences of a growing number of companies make a strong case that email is not the most effective tool for communication. Not only does it interfere with work-life balance, it can also have a detrimental impact on productivity.

You may be thinking of sharing this article but, in the spirit of this research, maybe you should share it via social media instead of email.