Node4 Limited / node4.co.uk maintains CBL-listed, botnet-infected IP addresses rated up to "medium" for the amounts of spam sent during a 30 day period.
www.senderbase.org/lookup/?search_string=node4 (bottom of pages)
AND PEER ROUTING OF AS31727 REPUTATIONS:
http://bgp.he.net/AS31727#_peers (list of peer networks routing AS31727 - Node4 Ltd)
See my comments of the bad reputations of networks peer routing as31727:
www.mywot.com/en/scorecard/airtel.in (airtel.in / Bharti Airtel)