On Wed, 15 Apr 1998, Christopher Purnell wrote:
> Date: Wed, 15 Apr 1998 10:24:17 +0100 (BST)
> From: Christopher Purnell <cjp@???>
> To: exim-users@???, "Exim, Users, Mailing, List"@???
> Subject: Re: [EXIM] DNS
>
> Greg A. Woods wrote:
> > [ On Tue, April 14, 1998 at 09:48:20 (+0100), Christopher Purnell wrote: ]
> >
> > > If the target of a MX record must have an A record why look for a MX
> > > record if you can't find an A record?
> >
> > Because the algorithm for searching for the target mail host starts the
> > other way around -- As I think has been discussed in other followups to
> > this thread you must look for an MX first, and then the A's for all the
> > MX targets, and only as a last resort *may* you look for the A for the
> > target domain.
>
> Why is everyone misunderstanding me here? The order MX,A might be
> what is done for the original domain but A,MX is the order for
> unresolved targets of an MX lookup.
Uhmm.. no.. properly written MTA's do not look for MX records for the
targets of MX records.
search for MX for target domain
found - search for A records for targets of MX record(s)
found - attempt SMTP connection
not found - bounce, error: ? dns is broken
not found - search for A records for target domain
found - attempt SMTP connection
not found - bounce, error: no such domain
--
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