Good morning!
I was struggling with a lot of notification emails from Fail2ban.
After some research it turned out that my list of attackers is overlapping with these lists:
count of overlapping IP-s / blocklist
10 dshield (HTTP API)
12 greensnow (list)
30 spamhaus (DNSBL)
95 blocklist.de ("ALL" list)
So please consider including this list: https://greensnow.co/