Fighting spam via greylisting
jhuntwork at linuxfromscratch.org
Sat Apr 14 10:41:27 PDT 2007
On Fri, 13 Apr 2007 21:19:54 -0500, DJ Lucas <dj at linuxfromscratch.org> wrote:
> Auto whitelist on greylist? Auto permanent whitelist would be bad, I'm
> assuming this is just a retention policy?
The general policy is accept if the MTA appears in the database has having tried to deliver before. But the database is pruned regularly. From their site:
Postgrey does keep track not only of the first time a given triplet was seen, but also the last time. Entries that were last seen more than a defined amount of time ago (one month for example) get removed automatically.
Auto-whitelisting of clients
Clients which repeatedly show to be able to pass the greylist, are entered in a "clients whitelist", for which no greylisting is done anymore.
I don't know what the exact criteria is to be auto-whitelisted, but it doesn't seem to be overly liberal.
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