The links below are to articles that look at how to use Calibre to convert ebooks to the new Kindle format (KFX).

For more visit:
– http://blog.the-ebook-reader.com/2016/03/28/how-to-convert-ebooks-to-kfx-format-for-enhanced-kindle-typesetting/
– http://the-digital-reader.com/2016/03/28/how-to-use-calibre-to-convert-ebooks-to-kfx-format-for-the-enhanced-kindle-typesetting/