Creo Six Degrees 2.0 makes e-mail more useful by leveraging existing connections in your mail. Messages found by its Google-style search interface are automatically linked to related correspondents, files, embedded links, and more. A few clicks within your search results and you'll understand where this product gets its name.

Six Degrees will index any POP3 or IMAP e-mail account. We tested it on a Microsoft Exchange account via IMAP. The initial pass took over 3.5 hours to index about 8,000 messages. Subsequent index updates went much faster. In addition to the index, the program created a local copy of the IMAP mailbox, requiring over 300MB of disk space.

The Six Degrees user interface is entirely browser-based, so it's familiar and easy to pick up. A handy Directory page links to predefined searches, such as frequent or recent correspondents, and a list of all distinct e-mail domains found. On the other hand, Six Degrees feels Web-slow, and the search doesn't always behave as expected—for example, without special syntax, message searches don't include the To and From fields. And the nonsearchable Help replaces the program itself unless you remember to open in a new window.

In addition to navigating existing connections, you can create "projects," linking specific messages, correspondents, saved searches, and files. A project organizes related items without actually moving them, and each project has a bookmarkable local URL. Items such as new messages with matching subjects or new mail from included correspondents automatically appear in the project, which can be exported as an RSS feed.

Creo Six Degrees excels at revealing existing connections and making new ones through user-defined projects. Its search mode, while vastly faster than that of Outlook 2003, is slower than that of X1 Search 3.0, and we weren't pleased with the requirement to make a local copy of IMAP-based mail. If it's as important to you to find the context of messages as it is to find the messages themselves, or if you need some hints to locate what you're looking for, Six Degrees is a good choice. If you just want fast searching, choose X1 instead.