An essential need Rated 5 out of 5 stars

I wonder why Thunderbird doesn't have this feature by default. I saw "import" under "tools" menu, but don't expect that it only be able to import address-books.
But using this addon we can also import/export mails/folders as mbox, eml and other formats.

This review is for a previous version of the add-on (2.8.0.1).