Kjetil Torgrim Homme <kjetilho@???> (Do 04 Jan 2007 07:53:47 CET):
> On Tue, 2006-12-26 at 12:29 -0700, Chad Leigh -- Shire.Net LLC wrote:
> > I set up two low priority MX hosts that are virtual hosts
> > on the same machine as the normal mailhost. These lower priority
> > ones automatically defer everything that hits them. [...]
> >
> > I do greylisting use Marc Merlin's sa-exim with his greylisting
> > module added.
>
> this will break when the sending server uses Exim...
>
> here's the scenario:
>
> * server sends message to A (highest MX priority), and is defered
> due to greylisting.
> * server now tries to send message to B (lowest MX priority) which
> always defers.
> * server notes that B defers in retry database
> * some time later, it retries A, and it is successful.
Until here I understand it.
>
> repeat this for some time. eventually you get this:
>
> * server sends message to A, and is deferred due to greylisting.
> * server tries B, which defers. it looks in retry database, sees
> that B hasn't worked for a long time, and BOUNCES THE MESSAGE
> IMMEDIATELY.
Why should A defer again? Ok, probably because the grey list was
cleaned.
But why should the sending server now think that there are delivery
problems for a long time already?
Best regards from Dresden
Viele Grüße aus Dresden
Heiko Schlittermann
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