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; I guess the
> > assumption is
> > that those hosts are backups of lower priority, and they will thus
> > pass the
> > mail up to higher priority servers - including us. So this logic is
> > there to
> > stop possible mail loops.
>
> 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.
--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book
