Best way to export from thunderbird to Outlook express is:
Navigate to your Thunderbird profile folder, usually found in C:\Documents and Settings \ [User Name] \ Application Data \ Thunderbird \ Profiles \. Here Thunderbird stores your Inbox, Sent mail, etc as two files – one with, one without .msf extensions.
Convert these files to .eml files by downloading IMAPSize (from here
http://www.broobles.com/imapsize/index.php). Go to Tools > mbox2eml. Select the file without the extension. Choose a storage location for generated eml files and click ‘Convert’.
In Outlook Express select the local folder, such as Inbox, to which you want to import messages. Open Windows Explorer, locate the folder where you stored the new .eml files, and simply drag and drop them into the Outlook Express window.
be warned it will take a while as it does it message by message.
And to convcert the address book yiou need this utility:
http://www.joshie.com/projects/dawn/download.html it does it automatically easy as pie.
Badg3r.