このアドオンについて
If you are using IMAP and hold all your letters on server each time you reinstall Thunderbird you may need to sort all your e-mails. This plugin can do it for you! You can specify how many messages you would like to sort, how many messages fetching criteria should be finded to create new folder. After analysing is finished you will see list of folder suggested for creation and finally decide what of them do you want.