For more than a decade, the look and feel of e-mail inboxes has remained agonizingly static. Many of today's mail applications can predict the address a user is typing and show threads of conversations, and some are searchable by keyword, but none provide a truly innovative way to view e-mails.

Now, a startup based in San Francisco called Xobni ("inbox" spelled backward) has released a test version of software that gives Outlook, at least, a completely different feel. Xobni's goals, says cofounder Adam Smith, are to pull out relevant but sometimes buried information from a person's inbox and other folders, and make it easy to find. Overall, Smith and cofounder Matt Brezina succeed in building an attractive, useful interface to show people a side of their inbox that they rarely see, such as phone numbers buried in the bodies of messages and social networks between e-mail correspondents.

The idea of indexing e-mail is certainly not new, and Google Desktop has a feature that goes through a user's Outlook files to make searching them easy. But what makes Xobni distinct is that it turns e-mail from a message-based system into a people-based system. When a Xobni user highlights an e-mail in her inbox, a panel pops up showing useful information about the sender. If a picture is available, it appears, as does a bar graph showing the times of day when the sender has e-mailed the user. This is useful for gauging when that person may be online and working in the future. Xobni keeps track of the number of e-mails the user and sender have exchanged and even ranks the sender in terms of the frequency of e-mail contact.

An extremely useful feature is one in which Xobni displays the phone number of the sender, pulled out from an e-mail signature or the body of an e-mail. What's more, the software is able to provide a list of people who have also been included on e-mails with the sender and user, revealing a social network that would most likely otherwise go unnoticed. For instance, when looking at the social network of one of my more well-connected colleagues, I found e-mail addresses for a couple of people who weren't in my Outlook contacts and whose e-mail addresses are useful to know.

The Xobni panel also includes a list of recent e-mail conversations organized by thread and sorted by date, and a list of files exchanged between the user and the sender, likewise organized by date. In addition, Xobni keeps track of the last time the user and senders were in contact with each other, providing a view of people the user might not have e-mailed in a month, three months, or a year or more.