Originally Posted by rstoothoff
Thanks to Calibre, I created decent-looking .mobi and .azw3 files from an InDesign-based .epub file. (Calibre delivered the goods, whereas both Kindlegen and the InDesign plug-in did not.) I downloaded the .mobi file to Amazon, and the book is now in the Kindle store, but only (so far as I can tell) in the .mobi format. KDP won't upload the .azw3 (KF8) file. So how can I make that available in the Kindle store?
Unpack the azw3 and use Kindlegen on it. That will give a combined file with both AZW3 and Mobi in it. But the Mobi might not be as well formatted as the calibre-produced mobi.