I just saw the news that Thunderbird 2.0 Beta 1 is now available. The link was hard to find off mozilla.com, but a quick google turned up the Release Notes page which contains the download link.
So why am I mentioning this? Well, because I haven’t been able to get Thunderbird 1.5 to run reliably on my new laptop (a Dell running Ubuntu Edgy), but I’m not exactly thrilled with Evolution just yet either. (I’ve actually been using mutt lately, if you can believe that; though it’s not the silver bullet either.) I haven’t spent much time in Thunderbird, but I’m hoping that it’s extensibility helps the customization a bit. (At the moment, I’m really missing Mail-Act On’s ability to bind a filter to a key-command in Apple’s Mail.app.)