Bug#658878: exim4: does not use other smarthost when one fails to resolve

[Tim Bagot]

Andreas Metzler wrote:
> Debian is setting host_find_failed = defer, i.e. "lets try again
> later", matching the historic behavior of exim3. - This makes exim
> work better for intermediately connected hosts by queuing mail instead
> of freezing it.
> 
> Afaiui by setting host_find_failed = ignore (and keeping
> host_all_ignored  at its default value of defer) we could fix this
> issue. - For systems with just a single smarthost listed the behavior
> would be unchanged, for systems like yours with multiple alternatives
> listed exim would ignore permanently unresolvable hosts and try the
> othere ones.

Thanks. I have since tested this modification on a non-production system,
and it does appear to do exactly the right thing, for a single smarthost,
for multiple smarthosts all unresolvable, and for multiple smarthosts with
at least one still available.


-- 
Tim Bagot
BlueArc Engineering, now part of Hitachi Data Systems