Thx Harry, the azw3 option is checked in the Kindle driver. I tried multiple things (in calibre 0.8.68):
- convert to MOBI with selecting "new" as MOBI file type
- convert to AZW3
When sending the book to the Kindle, I cannot choose the azw3 format, only the mobi format (which has extension .mobi). I assumed the Kindle driver was not yet updated to accept azw3 format files as this capability exists only since yesterday on KK (despite the very fast update cycle of Calibre :-)
If you have other ideas about options I missed or how to do this automatically, I would appreciate it.