Author: Peter Bowyer Date: To: Exim, Users Subject: Re: [exim] Extremely Simple(?) greylisting with exim?
On 05/01/07, Andrew Johnson <andrew.johnson@???> wrote: > >> Does it make sense to deliver to the 2nd MX if we know the 1st MX does
> >> not accept mail for the address?
>
> >You can certainly argue that it does not, because in a classical
> configuration, the 2nd MX is just going to forward the
> >message to the first.
>
> However, one of the reasons people have a secondary MX is so that they can
> still take ownership of a message even if it could not be delivered to it's
> final destination.
The 'classical configuration' is become increasingly less common,
though. For example, the infrastructure we use to support 1000-odd
domains has 3 geographically-distributed MXs, each of which is able to
perform aliasing and final delivery to distributed mailstore servers
or customer MXs.
A 4xx from one of these servers due to some local problem should imply
nothing about whether another is likely to be want to handle the
message.
