The Thunderbird 2 e-mail application comes from Mozilla, the same organisation responsible for releasing Firefox, the popular open source Web browser. Firefox has become the preferred tool for many people who reject Microsoft's Internet Explorer. However, will users seeking a Microsoft e-mail alternative turn to Thunderbird?

The answer for open-source aficionados, especially those who use Linux, is probably 'yes'. Mac users, however, are likely to use Apple's Mail, whose fans insist is faster. Although Windows users can pay for Outlook or opt for Microsoft's smaller, free, Windows Live Mail (which succeeded Outlook Express), we think Thunderbird is a highly attractive alternative for these users.

Setup and interface
Downloading the 6.4MB Thunderbird 2 for Windows took several quick minutes in our tests. On one Windows XP SP2 PC, we imported all of our corporate work e-mail settings from an Outlook account we'd been using for 42 months. That process took nearly 20 minutes. It imported our dozens of in-box folders, but those and the in-box were empty. We had to consult online help to work out how to get new messages to populate the in-box. On a Windows Vista notebook, we set up Thunderbird only to read messages from a rarely used, 24-month-old Gmail account; that process was nearly instantaneous.

Setup with the free Windows Live Mail was similarly foolproof. By contrast, however, we were glad that Thunderbird didn't ask to change our default browser settings. Nor did it litter our desktop with unwanted icons, as so much freeware often does. Unfortunately, we can't say the same when installing Microsoft Windows Live Mail in a bundle with its otherwise good Windows Live Apps package.

Features
Once Thunderbird 2 is up and running, its layout should be familiar to anyone who has dabbled in Outlook. Messages appear in the centre, with folders in the left pane and a menu of commands and options along the top of the window. We're grateful for Back and Forward buttons that help with navigation.

Thunderbird offers many small yet welcome advantages, such as text tagging. That lets you describe the content of, and later quickly retrieve, an e-mail or RSS feed. Tags also let you classify and prioritise messages, such as for work or for handling later. Although we didn't use a timer, we felt that search features were faster in Thunderbird than in the revamped capabilities of Microsoft Outlook 2007. Of course, Thunderbird offers other staple e-mail features, such as a spelling checker and warnings when you receive suspected phishing messages from scam artists.

That said, there aren't as many features in Mozilla Thunderbird 2 as in the full edition of Microsoft Outlook. For instance, we couldn't find a way to attach pictures to contacts. Nor could we preview Office documents within e-mails. While we were happy to see our Outlook contacts imported in their entirety, we disliked the fact that Thunderbird opened a separate window to display them.

Also, we wanted to use Thunderbird on a single computer to read e-mail from various sources as well as RSS feeds. Initial setup, which let us make only one of those choices, didn't make it easy to determine how to do that. Unfortunately, we found it clumsy to set up a signature line (done by setting up a message template) and an automated e-mail reply.

Rather than being managed within a closed corporate ecosystem, many passionate Mozilla developers update Thunderbird. This community has created hundreds of add-ons. Although Thunderbird lacks a calendar and to-do list tool, you can add those separately through Mozilla's Lightning and ReminderFox. That's good news for those willing to search, but a potential hassle for those who'd like everything pre-installed from the start.

Thunderbird renders HTML e-mails via the Firefox browser, which is good. Many users of Microsoft Outlook, on the other hand, complain that it uses a stale version of HTML that breaks the full formatting of some messages.

Service & support
Thunderbird provides online support only, which is reasonable for a free product. Mozilla's Help pages include a step-by-step tutorials with well-illustrated screenshots, as well as FAQs and keyboard shortcuts. However, we wish we could have searched directly within Thunderbird's interface for topics, such as setting up automated messages.