Re: [exim] zone_data expansion oddity

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Author: Magnus Holmgren
Date:  
To: exim-users
Subject: Re: [exim] zone_data expansion oddity
On Thursday 08 March 2007 10:32, Philip Hazel wrote:
> On Wed, 7 Mar 2007, Derek Buttineau wrote:
> > On 2007-Mar-07, at 7:58 AM, Magnus Holmgren wrote:
> > > The way things work is that if Exim finds itself in the host list,
> > > all the
> > > subsequent hosts in the list are also stripped.
> >
> > Is there a way to override this logic?
>
> No. It is behaviour that is required by RFC 2821:
>
>    If it determines that it should relay the message without rewriting
>    the address, it MUST sort the MX records to determine candidates for
>    delivery.  The records are first ordered by preference, with the
>    lowest-numbered records being most preferred.  The relay host MUST
>    then inspect the list for any of the names or addresses by which it
>    might be known in mail transactions.  If a matching record is found,
>    all records at that preference level and higher-numbered ones MUST be
>    discarded from consideration.  If there are no records left at that
>    point, it is an error condition, and the message MUST be returned as
>    undeliverable.  If records do remain, they SHOULD be tried, best
>    preference first, as described above.


MX records, yes. However, manualroute is, well, manual, so it can be argued
that this rule doesn't have to be obeyed (as long as one knows what one is
doing).

What happens if hosts_randomize is set? Is the randomisation performed after
the local host and subsequent hosts have been discarded, or does Exim
remember that the list is randomised and in that case refrains from
discarding hosts following any occurrences of the local host in the
(randomised) list, or is it necessary to avoid having the local host in the
list, lest the list be randomly truncated?

-- 
Magnus Holmgren        holmgren@???
                       (No Cc of list mail needed, thanks)


"Exim is better at being younger, whereas sendmail is better for
Scrabble (50 point bonus for clearing your rack)" -- Dave Evans