NNTPGrab

I installed rpm to configure repo for Fedora 15 but I get following error messages :

$ LANG=C sudo yum update nntp*
Loaded plugins: langpacks, presto, refresh-packagekit
Could not retrieve mirrorlist http://nntpgrab.nl/releases/fedora/mirrorlist-15 error was
14: HTTP Error 404 - Not Found : http://nntpgrab.nl/releases/fedora/mirrorlist-15
Error: Cannot retrieve repository metadata (repomd.xml) for repository: nntpgrab. Please verify its path and try again