[exim] callout

Hello all,

How can I do the following,:

Keep all my domains in a local file (/etc/exim/mailertable). and in this domains list have a "*" which then applies to all domains.
So when i recieve email exim will look the domain and up and what server it is on and do a callout check to that server, and then decide wether to accept the email or not. (the same with delievery).

Example of mailertable file:
test.com        :    192.168.0.1
firewall.com    :    192.168.0.3
*                    :    192.168.0.254

Thanks,
Michael