Even in the age of Facebook and Twitter, email remains one of the top three applications (along with the browser and word processor). This makes the need for an absolutely top-notch open source program in this category all-the-more important.
The obvious candidate is Thunderbird, Firefox's sibling. For many years, Thunderbird was rather neglected. That started to change with the appointment of David Ascher to head up a new Mozilla team, Mozilla Messaging. Good news, but I've yet to see any real lift-off for Thunderbird: maybe Thunderbird 3, currently in beta, will be the inflection point.
One thing that might help Thunderbird gain some momentum is to build out the ecosystem around it, as happened with Firefox, both in terms of add-ons and through third-party development. Here's one sign that something similar is starting to happen for Thunderbird, thanks to the new Postbox:
A new kind of messaging application, the Postbox email client helps you spend less time managing email and more time using email to get things done. Postbox automatically analyzes your e-mail messages, documents, photos, and links to web pages; then it catalogs all this information making it faster to search for and retrieve.
Easy-to-use tagging features let you organize messages the way you want and then focus on one project at a time without missing out on important new messages. You can also gather messages by conversation, annotate messages and create to-do items that appear in mailbox windows.
Not only is the code based on Thunderbird, but most of the start-up's team have strong links to Mozilla. Here, for example, is the background of Scott MacGregor, one of the two founders:
Leveraging his prior decade of experience in developing email applications for Netscape and Mozilla Corporation, Scott created Postbox to make email more powerful and efficient. Prior to founding Postbox, Scott was a lead engineer at Mozilla Corporation, where his after-hours efforts led to the invention of Thunderbird. Scott started out his career developing e-mail and messenger products at Netscape.
A commercial version of Thunderbird would be good news for the latter, since it would allow companies to gain a higher level of support than hitherto possible. Sadly, Postbox is only available for Windows and the Mac currently. Nor is it possible to take the source code and hack it into a version for GNU/Linux: curiously, the company has not yet decided whether Postbox will be made available as open source. As they told me:
it is still early in our development, and we don't have that completely finalized yet. Options for business models and interest from potential investors could influence our thinking here.
Now, I'm obviously biased, but I don't see how they can hope to compete against Microsoft's free Outlook unless they, too, are free. There are plenty of other business models that would allow the company to thrive (support, customisation, revenue from search boxes etc.) The upside of doing so is considerable: direct support from users, free marketing from direct personal recommendation etc. Let's hope Post box gets the message.