On 2022-04-07 at 03:19:34 UTC-0400 (Thu, 7 Apr 2022 15:19:34 +0800) Jeremy Ardley <jer...@ardley.org> is rumored to have said:
> Off topic, I'm now running postcreen on the mail servers. Is that an > efficient way to limit spammers? Would I get better results if I greylisted > as well as postscreen? Or instead of? Postfix's postscreen layer is very good, and pretty much eliminates the most obnoxious 20-80% of spam. Where in that range you hit depends on the sort of spam you are tageted by. You should probably NOT enable its "after 220 server greeting" tests. Read the POSTSCREEN_README document in the Postfix docs. Greylisting can catch more spam, including nearly all of what a conservatively configured postscreen would catches. However, it will also delay a lot of legitimate mail and on a large enough (or unlucky enough) system, it will need oversight to maintain a set of special cases of senders whose perfectly legitimate practices cause problems with greylisting. I don't use greylisting anywhere, because it creates a support burden. People will complain about delayed legit mail. Some legit mail will be blocked until it is given special accommodation. The same is true of the "after 220 server greeting" tests in postscreen, which are effectively a sloppy sort of greylisting. -- Bill Cole b...@scconsult.com or billc...@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) Not Currently Available For Hire
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