The current junk mail filters in Mozilla Thunderbird are good, however the UI and behavior of the junk filter is not that good, yet.
I know much work is being done to improve this feature. There are several bugs filed with RFEs to make junk mail more effective and more logic in it’s actions.
Like right now, the junk filter is run AFTER all messages are downloaded from the server… This is not very logic since users would normally begin browsing mails right after each message is downloaded. It would therefore make more sense to check for junk after EACH message is downloaded.
Of course there is also the fact that junk mail triggers the mail-notification, but that bug is being worked hard on.
I do however like how Thunderbird is much improving in the ways of handling junk, like you can now select not to allow HTML or loading of remote images if a mail is junk. Also check out this document on the future of junk mail filtering, SEXY!
Thunderbird is the future, I just wish there were more developers on it, and that they would listen to MY requests :)

Personally, I believe that Tolkien’s novels have been destroyed by Jackson’s interpretation. He has left out so many important scenes that some thing that happen later on are not as evident as they should be. Also, scenes from the fellowship are in the two towers and some scenes from the two towers are in the return of the king. If Jackson had have stuck to having all the scenes with their corresponding book, then it might have helped a bit. Overall, i was very disappointed.
I’ve been using Thunderbird thru several versions. It worked. Not brilliant but it worked and it was safer than OE. It totally lacks format controls above a kindergarten level but I’ve lived with it. What has me so upset that I’m posting now is some bug were junk mail controls no longer run. Junk mail is not removed to the junk folder even when manually marked. It just sits whereever it is. I can’t get any help for this and it’s frustrating. Enough so I’m about to admit failure, give up, and go back to OE.
The support for Thunderbird seems minimal to none for the average user. So sad, I’d had high hopes. The older beta versions all worked much better, imho.