@tommy123 It is a freq asked feature but there is no simple solution.
The recipe mechanism doesn't allow that to be done in a reliable manner because that would mean waiting till the book was generated (to be sure) and then marking the articles as read (or else..). Recipes just work till the items are fetched and then forwarded to the book compiler. They don't receive a confirmation of successful book generation.
Perhaps the new plugins feature of calibre would be a better place to do that. Something to think about..