Hello,
On Wed, Jan 31, 2007 at 09:25:52AM +0100, Patrik Jansson wrote:
> We have a set of primary mail servers, let's call it A. We also have two
> backup mail servers B and C (which should operate on the same MX
> priority but a slightly different problem occurs even if they wouldn't).
>
> Figure the case where a mail is to be delivered to a particular mail
> server in the set A but that server is down so it is delivered to B
> instead. B then tries to deliver to the primary server but it's still
> down so it goes on in the MX priority and sends the mail to C insteads.
> And here's where the loop begins I think, because C will then re-send it
> to B won't it?
No, it won't, if the priorities are equal.
This behaviour is documented in chapter 17 of the fine manual:
<quote>
MX records that point to the local host, or to any host name that
matches hosts_treat_as_local, are discarded, together with any other
MX records of equal or lower priority.
</quote>
And please, don't steal threads.
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