Re: [exim] temporary errors (LDAP failures) while routing

On 2009-07-14 at 17:25 +0200, Lutz Preßler wrote:
> dest_a:
> driver = manualroute
> domains = example.com
> condition = ${lookup ldapm{..URL..}{yes}{no}}
> route_list = * host_a bydns
> transport = internal_smtp
>
> dest_b:
> ...
>
>
> the following problem is not trivial to solve it seems:
>
> As "9.5 Temporary errors in lookups" of the spec states
> Lookup functions can return temporary error codes if the lookup cannot be
> completed. For example, an SQL or LDAP database might be unavailable. [...]
> When a lookup cannot be completed in a router or transport, delivery of the
> message (to the relevant address) is deferred, as for any other temporary
> error. In other circumstances Exim may assume the lookup has failed, or may
> give up altogether. -
> if _one_ destination system is not available, messages to _every_ user in this
> domain will be deferred (even those at other destinations).

I believe that this conclusion is false.

It's for precisely the problem of not knowing how other LHSs will be
routed that the dnslookup and manualroute Routers have a
"same_domain_copy_routing" option, which defaults to false.

As long as you don't set same_domain_copy_routing then you should be
fine.

-Phil