On Tue, Nov 25, 2014 at 08:10:28AM -0800, Darren Pilgrim wrote:
> >For example, if a domain has MX records, but we drop them all, it
> >may not be appropriate to then use the A/AAAA records. Rather, it
> >seems that such a domain is unreachable. So the "IGNORE" could
> >be augmented by:
> >
> > IGNORE_FAIL_IF_EMPTY
>
> I can definitely see the utility of that. I think in production I would
> want "defer if empty" with logging stating that the set of A/AAAA nexthops
> is empty after filtering. That way I'm not bouncing email on what could,
> ironically, be a transient DNS issue.
Well, actual DNS answers are not supposed to be transient issues, those
are the result of timeouts and other lookup failures, however, if we
provide the hard-fail feature, creating a soft-fail variant is perhaps
not unreasonable as a matter of completeness.
--
Viktor.
