In 1971, in a lab in Cambridge, Mass., the computer engineer Ray Tomlinson invented e-mail. By 1972, we can imagine, users of the new system might have been experiencing two novel, dissonant sensations: Endless joy at the ease and power of e-mail, and frustration at how badly it did everything they wanted it to do. We might like to think that our current problems with e-mail are new, caused by insidious "network effects" -- basically, by the fact that so many people are now online and e-mailing. But e-mail was ever thus: For almost two decades, researchers have been conducting "field studies" on e-mail users in office settings. In every study, even during the earliest days of e-mail, when mail volume was a fraction of what it is today, "active e-mail users" have reported feeling overwhelmed by mail, critically close to losing all control. The pain we feel in e-mail is nothing new.

What's curious, though, is that there is no set number of messages at which people begin to feel adrift with e-mail -- depending on personality and work habit, some people fall apart at 20 messages in a day, while others can deal with 200. This goes to a deeper fact about e-mail, one that explains many of the shortcomings of today's e-mail programs: Everyone uses e-mail differently. There is no accepted way to use e-mail; nobody ever tells you how to use it, or what to use it for. This is remarkable, since most of us use most products in similar ways -- each of us operates an automobile or a Web browser or a cellphone in just the same way as everyone else. E-mail is a fundamentally different kind of application. Once we start using it, we all end up working with e-mail in a highly personalized manner.

The wide variety of ways in which people use e-mail was first discovered in 1988 by Wendy Mackay, an MIT researcher who studied two dozen "extremely active" e-mail users at a large corporate research lab. By tracking how people worked with e-mail, Mackay found that there are a few classic e-mail user "types," the two most memorable of which were the folks she called "prioritizers" and those she labeled the "archivers." Prioritizers are people who manage their mail by simply not paying very much attention to it. For them, e-mail is just a tool at the workplace, like the phone or the fax machine -- it helps you do what you need to do in order to get your main job done. "My goal is to read as little mail as possible," a prioritizer named Mary told Mackay. "I try not to read mail more than once a day; I budget my time." Mackay wrote that Mary's colleagues were often frustrated because she did not always respond to her mail. Mary's defense was that if people really needed her urgently, they'd call her on the phone.

The more interesting e-mail personality belongs to the archivers, the people who save every piece of mail that comes to them, and who think of e-mail not just as a tool to help them with work and life but as a proxy to life itself. In Mackay's study, one archiver, a hapless computer scientist named Ralph, typified the breed. Unlike Mary, Ralph thought of mail as "an absolutely essential communication medium for both his job and his personal life." But Ralph's e-mail was a mess; his in box, Mackay wrote, was "always a jumbled mix of unseen messages, unclassified messages, and messages that remind him to do something." Ralph was unable to delete any messages out of a fear that he might get rid of something important: "What percent of the ocean don't you like?" he asked Mackay.

This wasn't an idle fear on his part -- Ralph actually did use the messages in his in box as a guide to what tasks he needed to perform at work, and deleting e-mail could have been dangerous. As messy as it was, his e-mail outlined some kind of rough order for his life. And although Ralph did at times try to organize his messages into folders, he could never come up with a good scheme to help him find the messages later. He recognized that he desperately needed help -- "he feels as if the situation is completely out of control," Mackay wrote.

It would probably be pleasant to be a prioritizer like Mary, unconcerned about missing important messages, happy to spend just a few minutes a day with e-mail, content to delete whatever you no longer find useful. In the digital age, though, Mary's attitude toward mail seems a tad quaint. The key problem with e-mail today is that, as the medium has become more and more central to our lives over the years, we've all been pushed -- some of us against our wishes -- toward Ralph's position, characterized by a need to save every message we get. You don't have to be a journalist to consider it verboten to delete a single piece of e-mail. There are a host of professionals for whom this is true today -- computer programmers, academics, attorneys, financial experts, Web designers, bloggers, eBay salespeople, and probably dozens of others. And in the future, as our jobs become more tightly centered on communication, the archivers' way of life will surely become even more dominant.

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