I recently attempted to report spam that was sent to me from [136.144.219.231]. This address is being routed by AS20857 (ORG-SI6-RIPE / Signet B.V.) and the containing IP block (136.144.128.0/17) is registered to TransIP B.V. (NOTE: no associated ORG record) which appears to be just a different face of the same Dutch company (Signet). My spam report was sent to the abuse reporting address contained in the RIPE WHOIS record for the revevant ASN (AS20857) i.e. <abuse@signet.nl>. Of course, I included in the report a complete copy of the spam message I received so that the people on the other end could have a clear picture of the nature of this incident and those responsible for it. Unfortunately, Signet/transIP appears to be yet another in a succession of ISPs that have failed to grasp the seemingly obvious fact that enabling spam filtering on your own inbound spam reporting email address is counterproductive. Thus, for my trouble I received back: <support@signet.blue> (expanded from <abuse@signet.nl>): host mx.transip.email[86.105.244.9] said: 550 5.7.1 Our system has detected that this message is likely unsolicited mail (SPAM). To reduce the amount of spam, this message has been blocked. (4Kpghy5Bcvz1J9nY) (in reply to end of DATA command) Based on this rejection it is now my intention to locally blacklist all IPv4 blocks assigned to this ISP. A partial list of these is included below. Unfortunately, due to ongoing and longstanding issues with the RIPE data base (which I will be mentioning yet again on the RIPE db-wg mailing list, for all the good it will do) it is not easily possible to derive a full list of all of the IP address blocks assigned to this company, at least not in a simple automated fashion. Blocks assigned to ORG-SI6-RIPE (fully aggregated): 31.3.8.0/21 31.3.96.0/21 31.14.96.0/22 31.223.160.0/20 37.17.208.0/20 37.34.48.0/20 37.97.128.0/17 37.230.96.0/21 46.21.224.0/20 46.226.56.0/21 77.72.144.0/21 78.108.128.0/20 79.170.88.0/21 80.69.64.0/19 80.84.224.0/19 80.246.192.0/20 80.255.240.0/20 81.4.64.0/19 81.4.96.0/22 81.4.112.0/21 81.21.136.0/21 81.30.32.0/20 83.96.128.0/17 84.247.8.0/21 85.10.128.0/18 85.158.248.0/21 85.222.224.0/21 86.105.244.0/22 87.253.128.0/19 89.31.96.0/21 89.41.168.0/22 91.142.240.0/20 91.205.32.0/22 91.216.162.0/24 93.119.0.0/20 93.191.128.0/21 94.142.208.0/21 95.170.64.0/19 141.138.136.0/21 141.138.192.0/20 141.255.176.0/21 149.210.128.0/17 171.33.128.0/21 176.74.224.0/19 178.18.80.0/20 185.3.208.0/22 185.10.48.0/22 185.15.248.0/22 185.21.188.0/22 185.65.52.0/22 185.69.232.0/22 185.76.236.0/22 185.84.72.0/22 185.89.152.0/22 185.95.68.0/22 185.96.4.0/22 185.105.204.0/22 185.105.216.0/22 185.108.112.0/22 185.110.172.0/22 185.110.200.0/22 188.240.52.0/22 188.241.148.0/22 193.93.172.0/22 193.138.204.0/22 193.242.119.0/24 194.60.207.0/24 195.8.195.0/24 195.135.195.0/24 213.187.240.0/21 217.21.240.0/20 217.149.128.0/20