tcp dport { 143, 993 } ct state new meter dovecot4 { ip saddr timeout 1h limit rate over 2/minute burst 20 packets } update @blackhole4 { ip saddr timeout 1h } counter; tcp dport { 143, 993 } ct state new meter dovecot6 { ip6 saddr timeout 1h limit rate over 2/minute burst 20 packets } update @blackhole6 { ip6 saddr timeout 1h } counter;