Note: This review addresses v1.7.3 of the software.

Xobni is a free add-on for Microsoft Outlook. The reason behind the backwards name: This useful tool allows you to look at your e-mail inbox from a whole new perspective. The add-on improves management of messages and contacts, one of Outlook's biggest shortcomings. It provides functionality that Outlook should deliver natively, and does so without affecting the e-mail client's performance.

Xobni adds a pane to the right side of the Outlook interface that slides open when you need it and closed when you don't. When you install Xobni, it indexes your mail, so you can search for contacts and text. The add-on uses the indexed information to create contact profiles, as well. If you're reading a message from John Smith, for example, it shows the number of e-mail messages John has sent you, broken down by the time of day they were sent. From this information, you can tell if John tends not to respond until a certain time of day, so you can anticipate when he might reply to future e-mail.

Your contact profiles show (with a photo, if you have one) in the top of the Xobni pane; the application also displays each contact's phone number, which it extracts (with what proved to be amazing accuracy, in my tests) from e-mail messages. Below each contact profile, you see a thread of conversations you've had and files you've exchanged. You can quickly find and view threads by specific topics; a slider control reveals more or fewer lines of the conversation.

Xobni also creates a kind of social network by keeping track of any additional recipients on e-mail messages sent to you. You can add your friends' contacts to your address book or quickly draft e-mail to them from within Xobni. If you have Skype's VoIP service on your PC, Xobni integrates with it nicely; a quick tap of a phone number within a Xobni profile generates a SkypeOut call. Two template options also appear in this pane: One creates a blank e-mail, and the other creates a meeting request. For the latter, Xobni saves you time by autofilling the request with open time slots pulled from your Outlook Calendar.

You can use Xobni for simple searches within Outlook, too, and it often returns results much more quickly than Outlook's search does. Xobni also goes far beyond speedy searching, providing logical social information and extended functionality that Outlook simply doesn't. Instead of treating mail conversations, contacts, and calendars as separate entities, Xobni weaves them together in a responsive, intuitive interface.

--Kevin C. Tofel