Originally Posted by st_albert
What Charlski said, except that ID4 export to epub is just a starting point.
It will need some tweaking in order to become an epub worthy of the name. The biggest fault is that all the body of the book will be in a single .xhtml file within the epub, which will break some readers.
Starting from the ID4 exported epub, you will need to:
0) edit with Sigil (0.23)
With it you can break the large xhtml into chapters, clean up the styles, add/remove images, edit text, etc.
Then if needed:
8a) goto 0 if needed
9) you're done!