1.필터 생성
/etc/fail2ban/filter.d/dovecot-pop3imap.conf
[Definition] failregex = (?: pop3-login|imap-login): (?:Authentication failure|Aborted login \(auth failed|Aborted login \(tried to use disabled|Disconnected \(auth failed).*rip=(?P<host>\S*),.* ignoreregex =
2.설정 파일에 규칙 추가
/etc/fail2ban/jail.conf
[dovecot-pop3imap] enabled = true filter = dovecot-pop3imap action = iptables-multiport[name=dovecot-pop3imap, port="pop3,imap", protocol=tcp] logpath = /var/log/maillog maxretry = 20 findtime = 1200 bantime = 1200