[exim] message routing after delivery errors

Hej,

is it possible to run another router after a dnslookup router accepted a
message, but the transport temporarily failed to deliver it?
The reason I want to do that is, if my backup Server can't deliver a
message to its primary MX, I want to store it in an bsmtp file for
further processing. But the defer causes exim to cease delivery and
leave the message in the queue, where I really don't want it.

The exim doc says "No further processing of the address happens in this
delivery attempt." for temporary errors in routers, I assume the same is
true for transports, so I guess there's no simple way to do what I'd
need, or is there?


TIA,
daniel