+ http://www.spamhauswhitelist.com/en/
+ looks like a parked domain with ads
+ http://stopspam.org/rblcheck/index.php
+ aka dul.pacifier.net
+ http://www.stopspam.org/rbl-info/
+ stopped in 2013
+ http://countries.nerd.dk/
+ unable to connect, also for nerd.dk
+ http://dul.ru/dul.en.html
+ DEAD for sale
+ http://dns.measurement-factory.com/surveys/openresolvers.html
+ dead
+ »The following text describes past open DNS resolver surveys and an associated DNS lookup service that has been long shut down«
+ http://www.sectoor.de/tor.php
+ timeouts
+ http://anticaptcha.net/
+ for sale
+ http://blacklist.lashback.com/
+ query zone: ubl.unsubscore.com
+ provider’s website https://lashback.com/ seems alive and active (news entries from 2023) but does not link to the blacklist
+ rsync URLs seem dead, so does the download url
+ http://blacklist.woody.ch/
+ no entries in the displayed "top 100"
+ may have been absorbed into the swinog blacklists, see antispam.imp.ch
+ http://cbl.abuseat.org/
+ https://www.abuseat.org/
+ changes to the CBL that occured in January 2021. In short, the CBL infrastructure was replaced by the Spamhaus XBL structure
+ http://dnsbl.burnt-tech.com/
+ domain is for sale