Linux - Postfix - zapobieganie floodowaniu serwera

Witam,

Pewnie jest tu ktoś kto konfigurował postfixa na linuksie i może mi cos poradzić. Otóż często zdarza mi sie sytuacja podobna do tej:

 
Sep  7 20:00:51 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:51 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:51 SERWER postfix/smtpd[22167]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:51 SERWER postfix/smtpd[22167]: connect from unknown[182.72.61.99]
Sep  7 20:00:51 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:52 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:52 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:52 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:52 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:52 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:52 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:53 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:53 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:53 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:53 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:53 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:53 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:54 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:54 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:54 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:54 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:54 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:55 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:55 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:55 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:55 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:55 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:55 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:56 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:56 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:56 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:56 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:56 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:56 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:57 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:57 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:57 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:57 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:57 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:57 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:58 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:58 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:58 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:58 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:58 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:58 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:59 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:59 SERWER postfix/smtpd[22169]: warning: hostname NSG-Static-099.61.72.182.airtel.in does not resolve to address 182.72.61.99: Name or service not known
Sep  7 20:00:59 SERWER postfix/smtpd[22169]: connect from unknown[182.72.61.99]
Sep  7 20:00:59 SERWER postfix/smtpd[22167]: lost connection after CONNECT from unknown[182.72.61.99]
Sep  7 20:00:59 SERWER postfix/smtpd[22167]: disconnect from unknown[182.72.61.99]
Sep  7 20:00:59 SERWER postfix/smtpd[22169]: disconnect from unknown[182.72.61.99]
Sep  7 20:04:19 SERWER postfix/anvil[22148]: statistics: max connection rate 17/60s for (smtp:182.72.61.99) at Sep  7 20:00:59
Sep  7 20:04:19 SERWER postfix/anvil[22148]: statistics: max connection count 2 for (smtp:182.72.61.99) at Sep  7 20:00:51
Sep  7 20:04:19 SERWER postfix/anvil[22148]: statistics: max cache size 1 at Sep  7 19:57:56

Nie wiem zasadniczo, po co ktoś coś takiego robi. Nie zdarzyło się raczej żeby ktoś mi zajechał serwer w ten sposób, ale z tego co widzę nieraz z tych samych ip, codziennie o róznych porach coś takiego mam w logach. Czy dałoby rady tak skonfigurować serwer, żeby powiedzmy po 10 takich próbach klienta na stałe zablokować? I nie chodzi mi o blokowanie na firewalu połączeń z tego ip na tym porcie (to musżę za kazdym razem robić ręcznie), tylko o jakieś rozwiązanie na poziomie samego serwera poczty.