Fighting spam via greylisting

Jeremy Huntwork jhuntwork at
Sat Apr 14 10:41:27 PDT 2007

On Fri, 13 Apr 2007 21:19:54 -0500, DJ Lucas <dj at> 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:

Automatic maintenance
    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.

Also there's:

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.


More information about the lfs-dev mailing list