Re: [exim] Limiting verification callouts to own hosts

On 15/11/06, Martijn Grendelman <martijn@???> wrote:
> Hi,
>
> I am trying to make my fallback mail server reject mail for non-existent
> users during SMTP, so I want to do recipient verification callouts to
> the primary mail server.
>
> The problem is, that the fallback also relays mail for some domains that
> have different primary servers, and I don't want to do callouts to those
> servers.
>
> Is there a way to restrict verification callouts to certain hosts?
>
> The fallback does not have any authoritative knowledge about which
> domains end up at OUR primary, that is decided during routing exclusively.

Thinking aloud - how about an extra 'accept' router with 'verify_only'
set, which is ahead of your router which ends up driving SMTP
deliveries.

This router's job is to determine which domains will end up at the
servers you don't want to call out to - presumably using the same
technique as your current 'live' router along with an extra list of
calloutable servers (or non-calloutable servers if easier).

Then any verification for domains which are destined for the
non-calloutable severs will resolve in the 'accept' router without
causing callouts.

Peter



--
Peter Bowyer
Email: peter@???