I see some strange errors in the fail2ban log (setup according https://www.howtoforge.com/tutorial...n-8-jessie-apache-bind-dovecot-ispconfig-3/2/) So I disabled al filters and enabled them one by one to find the problem. When enable "dovecot-pop3imap" I get this error Code: 2015-08-21 00:28:19,661 fail2ban.filter : WARNING Unable to find a corresponding IP address for ::1: [Errno -9] Address family for hostname not supported This is the code from the filter: Code: [Definition] failregex = (?: pop3-login|imap-login): .*(?:Authentication failure|Aborted login \(auth failed|Aborted login \(tried to use disabled|Disconnected \(auth failed|Aborted login \(\d+ authentication attempts).*rip=(?P<host>\S*),.* ignoreregex = what could be the problem?