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 Friday 02 March 2007 23:29, Derek Buttineau wrote:
> I'm experiencing a bit of an oddity in how my zone_data is being
> expanded on my queing server and I expect that it's due to combining /
> MX alongside of a secondary address. In my case it appears that when
> the message arrives at the non /mx address only the lowest MX from
> DNS is used, any others are stripped. I've searched most of the
> afternoon and can't seem to find any documentation to work around
> this, so any help would be appreciated. I've worked around my short
> term problem by temporary reversing the MX order in DNS so queued
> messages would be delivered to the new secondary DNS, but a long term
> solution would be nice to have :)
>
> Here's the situation, I have a manualroute router that gives data for
> the zone as follows (obfuscating the domain to protect our client):
>
> "clientdomain.com/mx:queue.csolve.net"
>
> On the main machines, this translates correctly as seen here:
> [...]
>    host mail.clientdomain.com [207.164.80.126] MX=10
>    host hummer.csolve.net   [10.10.19.4]     MX=20
>    host queue.csolve.net    [10.10.19.195]
> search_tidyup called

>
> However, on my queue server expansion works fine until the local name
> is removed from the host list, and then the only host tried is
> mail.clientdomain.com.
>    [...]
>    host mail.clientdomain.com [207.164.80.126] MX=10
> search_tidyup called

>
> Is this normal, and if so, is there a way to have it include the
> secondary MX from DNS even after the local host is removed?


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.

-- 
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