>
> My understanding of how to create an exim routing rule is
> very basic. An
> example would be most helpful.
>
There are some examples in the docs:
http://www.exim.org/exim-html-current/doc/html/spec_html/ch20.html#SECID123
Halfway down you get something like
through_firewall:
driver = manualroute
transport = remote_smtp
route_data = ${lookup {$domain} cdb {/internal/host/routes}}
You could alter that so that you lookup $local_part instead of the domain and use a straightforward text file using lsearch. That would give you something like (untested)
some_random_name:
driver = manualroute
transport = remote_smtp
route_data = ${lookup {$local_part} lsearch {/a/file/with/localparts/and/ip/addresses/to/send/them/to}}
and then have a file with lines like
user1: 10.0.0.1
user2: 10.0.0.2
etc
Does that help ? Please ask if you don't understand anything.
John