[Exim] multiple domains driving crazy

Hi everyone

I'm looking for an URL, giude or any sample script of a multiple domain
configuration. I've been through the archives, found many solutions, but
i still have 2 problems.

1) i have no idea how to get exim to deliver mail under
/var/spool/mail/$domain/$local_part

2) i set up to ise /etc/aliases.$domain instead of /etc/aliases, but every
time i got a mail like host.domain.tld, it starts looking for
/etc/aliases.host.domain.tld. This is what i don't have, because i set up
/etc/aliases.domain.tld. I have millions of hostnames, do i have to link
every hostname's alias to the domai's? I'm sure there is another
solution. Currently this is exim 3.33, compiled from source, on a redhat
system (6.2).

Currently i commented and/or erased everythnng from the config, so it
works fine as a simple mail server with its default config (i only changed
local_domain and stuff like that).

Exim worked fine before, but i'd like to use this feature.

Any help apprectiated.

thanks
adam