TODO
check and link (de)listing policy
NOGO: delisting for money
+ how long does automatic delisting take?
+ 7d is already quite long
+ anything >7d seems excessive and should probably not be used
check and link usage policy
check and link return codes
find newsfeed or mailinglist
https://www.spamhaus.org/organization/dnsblusage/
listing policies are clearly documented
return codes are clearly documented
+ history of grandeur and retaliation listings
+ https://www.heise.de/hintergrund/Spam-Golem-291396.html
http://www.surbl.org/
good reputation
lists domains/URIs