On Thu, 4 Jan 2007, Kjetil Torgrim Homme wrote:
> 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.
>
> 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.
That isn't right.
It is *recipients* that are deferred by greylisting, not messages. When
a recipient is deferred, Exim notes that the recipient, not the host,
has had a temporary error. (In the latest releases it is the
sender+recipient combination, not just the recipient.) So, the above
scenario will happen only if A defers *the same recipient* due to
greylisting on the second occasion, and as I understand it, this
shouldn't happen because the recipient was previously accepted.
--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book