Since ditching Outlook after Outlook 2003 (Outlook 2007, 2003 was fine in comparison) came around I’ve been using Mozilla Thunderbird as my ever faithful email client. Its fast, lightweight and not as bloated as Outlook is – couple it with Lightning and you’ll be laughing!
Thunderbird 3 brings some cool features for users with the biggest being tabbed message windows (and calendars etc). If you downloaded the new 3.x betas make sure you get Beta 4, the long standing issue with the Messagebox Summary file being corrupt has been finally addressed. Its been a pet hate for a long time now, sometimes searching a folder can corrupt an MSF (means having to go and remove the MSF so it rebuilds the index!), no more! Thunderbird will now fixup any problematic MSF files in the background, yay!
The search in Thunderbird 3 is a massive improvement over the other clients I’ve used, give it a go!