Am 21.06.2024 um 07:20:17 Uhr schrieb Jeff Pang via mailop: > postfix/smtps/smtpd[451948]: warning: unknown[211.184.190.87]: SASL > LOGIN authentication failed: UGFzc3dvcmQ6 > > I am afraid too many iptables will slow down the performance of > systems. do you have any suggestion for handling this case?
If possible, you can maybe restrict the submission server to IPv6 only if that is acceptable to your users. Nobody has yet tested login via IPv6. You can also use dnsbl (that may run locally) if that is faster. Is a valuable amount of those IPs listed in blocklist.de, spamhaus, uceprotect etc.? If that is also not an option, you may think about blocking entire networks if too much abuse comes from them and the abuse desk of the ISPs won't shut down those machines. -- kind regards Marco Send unsolicited bulk mail to 1718947217mu...@cartoonies.org _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop