> Doing it on MX would require dnsbl lookups for each MX server in all > received mail. > That would massively increase amount of dnsbl lookups.
I do not know if I would call it "massively". I already do `reject_unknown_client_hostname` check and 4 other dnsbl lookups. So I would do another 2 in addition to current 5? Yes, it is a lot, but thats how it is… My server does not serve a huge amount of real mail fortunately. > you still can block them locally using the rules above. I think it will not work, almost every spam comes from different domain. > On 03.08.17 11:09, Allen Coates wrote: >> Using the whole email address didn't work - I never sawthe same sender >> twice; Yes, exactly. Spammers have huge amount of hostnames. I do not think it is a good idea to build your own database. I even do not know how to build it, because I do not run MDA, I only forward emails… Simply put: I think it is difficult to fight against global botnets with a local black list :-) MJ
