Having belatedly updated to Firefox 2 , it was time to update to Thundirbird 2 as well. Unfortunately there isn't an official RPM for Fredora 6 (I have put of updating to Fedora 7). So I had to uninstall the RPM and install the new version manuall (using the binaries not the source).
Thunderbird 2 has a most annoying feature. whenever a new mail arrives a small popup would appear close to the taskbar showing an extract from that mail. I don't want to be notified of new mail and I most certainly don't want thunderbird to try to download my IMAP mail without my say so. Fortunately that feature can be switched off.
I use subversion for backing up all my documents and emails. Since getting my Macbook, my mail repository has been messed up. This of course has nothing to do with Thunderbird but itw was caused by my downloading mails onto the mac as well as the desktop. Almost every folder has a conflict. I checked around if the new thunderbird has a tool to remove duplicates. Conflict resolution is mostly about removing duplicates.
The good news is there certainly is a duplicate remover for Thunderbird and it works as advertised.