Am 07.08.20 um 22:54 schrieb Alain Gaudreau via mailop: > @Chris > > My vision of it is larger and includes a blacklist with the ability to > exclude and grey list certain hosts within the large blocks controlled by ovh > and the lot.
I'm working on a system which may in the long run include such a mechanism. This is implemented a postfix policy daemon, don't know if exim and sendmail can use similar policy handlers. Right now it can match on sender and SMTP client names, IP addresses, and ASN numbers of hosts, their MX and NS records, with combinations of conditions and exceptions, so it's pretty powerful already and helps me to keep out some prolific spammers who regularly acquire new domain names and hosting. I'll probably add some SPF handling that could be used in rules, although I'm not fond of SPF (it breaks forwarding which a good number of our users use.) In combination with exceptions it may still come in handy. Rules are currently configured using files, I'm changing that to have rules in a database together with logs and a web user interface so that users can see log records of mails they have received or that were destined for them but rejected, and can add their own rules and exceptions. The next step would be a kind of distributed reputation system which would allow users to share opinions about senders (good and bad). I'm thinking about using some kind of blockchain based technology which would avoid having a central source of opinions and a single point of failure. However, designing it such that it can have a good trust model, protection against spammers gaming the system, and provision of privacy is not easy, so don't expect something in the near future. Cheers, Hans-Martin _______________________________________________ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
