The release candidate download is now available from Mozilla's site. I've been using version 2 every day since beta 2's release in January. Though the program is not yet final, I've found it stable and up to the task of handling my daily e-mail chores. Making the switch is easy: Thunderbird 2 maintains all your filters and account settings, and you shouldn't have any problem jumping right into it. Like previous versions, Thunderbird 2 has a clean and straightforward interface that makes good use of available screen space.
One of the first things I noticed: mail pop-up alerts, one of Thunderbird's new features, which list the subject and sender of newly received messages in the lower-right corner of your screen and automatically fade after a few seconds. Each pop-up provides enough information on the latest few unread messages for me to decide whether I need to interrupt what I'm doing to switch to Thunderbird and read the e-mail.
As convenient as the mail pop-ups are, the introduction of tags in Thunderbird 2 is an even bigger boon for organizing messages. Tags replace the previous versions' labels function, which allowed you to assign just one of a handful of premade labels, such as 'Personal' or 'ToDo', to each message. Now, you can create an unlimited number of tags, and you can give any e-mail multiple tags.
Creating on-the-fly tags for any new topic does wonders for managing an ever-growing inbox. For example, I track antivirus news and products, so I created a new tag called 'antivirus'. A right-click lets me assign the new tag to any e-mail, and I can then quickly view only those tagged messages. I found right-clicking faster and cleaner than the typical method of creating a new folder for all such messages and then manually adding those messages to the folder. The feature is also particularly useful when combined with saved-search folders that show all messages with a particular tag (but keep your e-mail in one inbox). In the release candidate, however, the new tags have a few rough edges. For example, I changed the name of the default 'Personal' tag to 'PCW', but a filter I migrated from Thunderbird 1.5 still assigns 'Personal' to many messages. Also, when I assign multiple tags, Thunderbird seems to randomly select which tag's color it will use for the message; it doesn't allow me to designate a dominant color.
Brand-new in this release candidate is a Gmail account preset that fills in almost everything (server name, etc.) automatically when you configure Thunderbird to read your Gmail messages. You need only provide your name (for display) and account. The default settings will leave the messages on Gmail's servers so you can read them through both Thunderbird and Gmail.
The release notes list the same functionality for a .Mac account, but (not surprisingly) I didn't see such an option in my Windows version; it may show up only in the Mac software.
Other notable tweaks to Thunderbird include better customization options for viewing folders, and find-as-you-type searches. See the release notes for a full list of changes.
Unfortunately, Mozilla doesn't seem to have significantly improved its junk-mail filters, and my inbox still has plenty of spam. Also, Thunderbird still lacks a built-in calendar; however, a terrific and easy-to-use add-on called ReminderFox adds some basic calendaring functions, such as reminders to revisit a particular e-mail by a certain time.
Though Thunderbird 2 is not yet a final release, I found that the release candidate's new features and overall stability more than warrant your making it your primary mail client.
PC World.com (US)