Originally Posted by kovidgoyal
rss feeds usually only contain the most recent articles, there is no point in trying to use rss to download historical articles. Open the rss feed inn an rss feed reader or a browser and see how many articles are actually available.
That's the answer, calibre fetched all the articles in rss feeder.
Thank you for the great software and this answer.
Any suggestion on fetch old articles via calibre in this case?