Your inbox is stressing you out, a new study finds.

Here are some things about your job that could lead you to an early demise:

Your commute to your office.
Your morning coffee.
Your coworkers.
Your chair.
Your lunch.
Your happy hour cocktail.
Your commute from your office.

Now, we can add one more X to the X WILL KILL YOU work party: your email. Well, sort of. A new study, a collaboration between UC Irvine and the U.S. Army, measured the stress effects of email usage on a group of thirteen Army workers in a "suburban office setting." Researchers divided the workers into two groups, one that gave up email for five days (ahh!), and the other that proceeded, uninterrupted, with their inbox shenanigans. All the subjects were attached to heart rate monitors, and their computers were outfitted with software sensors that detected how often the subjects switched windows on their computers.

The finding? People who worked with email changed screens twice as often as the control group. (The specific stats: The subjects who used email switched windows an average of 37 times an hour, while the email-less workers switched an average of 18.) And all the screen-switching had definitive health effects, too: The frenetic emailers stayed in a steady "high alert" state, with their heart rates reflecting that. Those who abstained from email, on the other hand, "experienced more natural, variable heart rates."

Furthermore: Those with no email reported feeling more productive and better able to stay focused on their jobs' tasks. They also reported experiencing, as compared to their connected colleagues, fewer "stressful and time-wasting interruptions."

So "when you remove email from workers' lives," Irvine informatics professor and study co-author Gloria Mark puts it, "they multitask less and experience less stress." And that's important, because stress itself has been linked to a variety of health problems, including heart disease, auto-immune disease, obesity, and depression.

There is, however, a bit of a toothpaste-from-the-tube situation going on with the study's implications of The Dangerous and Maybe Murderous Inbox. Email may be stressful, but what's the practical alternative to it? It's one thing to give up email for five days in the name of science; it's another to give it up for five days, full stop. (Or for longer, full stop.) It's not like quitting smoking, or giving up fried foods, or going for a run: Abstinence from email is a decision that affects, by extension, anyone who might send you a message -- and anyone to whom you might send a message. In that sense, email is a matter of public health in the most literal sense. 

It's worth noting the small size of the study's sample, and worth noting as well why that sample is so small: The researchers had trouble recruiting subjects who were willing and able to give up email for five days. Even for a controlled, time-bound experiment. Mark argues that "email vacations on the job may be a good idea" in the name of stress prevention and general cognitive and physical wellness. And that may well be true. There's something, though, that may in the long run prove even more stressful than being on email: being away from it.