While I’ve got SMTP up and running, I can’t seem to change the contents of the email for fail2ban. Looking through a few forums, I’ve deduced that the contents of the email are in mail-whois-lines.conf. However, I can’t find the file anywhere in the fail2ban directory. Btw, I checked for hidden files already and couldn’t find it.
Just want to make sure you know that this is bitwarden_rs and not the fail2ban forum.
But those files are located in the action.d sub-folder, normally /etc/fail2ban/action.d/
Also for any further fail2ban specific questions i suggest to checkout: https://www.fail2ban.org/wiki/index.php/Main_Page