[AFreeBird]

I would not say that Thunderbird is better than Outlook, mainly because Outlook is much more than just a mail client. Now if you're speaking of Outlook Express, then yes, Thunderbird takes it, hands down.

The closest OSS equivelant to Outlook would be Novell's Evolution, which I do use and it can talk to an Exchange server, although I have no Exchange servers I have to talk to.

[rzeznikj at stout]

Though IIRC, you need to have the Exchange connector, which is often included with Evolution.