Eww... well, I guess you'll need T-Bird if you use the crappy freebie e-mail client, yeah.
Anyway, Firebird has every feature that Mozilla has and then some, with the extensions. You need to install the extensions for the features you want.
Well, even their freebie mail client has better mail filtering than most others. I used to use Eudora, but it was abysmal for that, and I detest Outlook.
Spiffy about Firebird though. Will get that later on and make the switch, but I'm kind of finished doing geek things today, since I had to replace my CPU fan with a better one, then put in my swanky new FX 5600 and then sort out sound card issues. All took longer than intended, as usual!