Qualcomm has released Eudora 6.0, a major upgrade to the company’s venerable email client. The marquee feature is SpamWatch, which is a new plug-in that employs Bayesian filtering to move spam-like messages to a new top-level Junk folder. In our testing since April, it has proven quite accurate. Another innovative feature is the Content Concentrator, which enhances the preview pane in any mailbox window (click the expansion triangle in the lower left corner of a mailbox window to show the preview pane) in two ways. First, it hides most headers and quoted text in an effort to help you focus on just the new text in a message, and second, if you Option-click to select multiple messages by sender or subject, the Content Concentrator displays all the selected messages (hiding headers and quoted text as appropriate) in the preview pane. It’s great for reading mailing list threads quickly. For Mac OS X users who don’t like multiple windows, Eudora now offers a mailboxes drawer attached to every mailbox window, and there are new toolbar and system icons for both operating systems. As is common with Eudora, there are oodles of smaller tweaks, improvements, and bug fixes. Eudora remains available in Paid (full features), Sponsored (free, with full features and ads), and Light (feature-limited but free) versions, although the SpamWatch feature is available only in Paid mode. Upgrades for Paid mode users are free if you purchased a Paid mode subscription within the last 12 months; they cost $40 if you have a Paid mode registration code from Eudora 4.3 or later; and you must buy a new copy for $50 if you’re a new user or have a registration code for a version of Eudora older than 4.3. You can download copies of Eudora for both Mac OS 9 (4.4 MB) and Mac OS X (4.2 MB).