[Exim] Exim 4.x + Cyrus 2.1.x == Mess :)

Does anyone know of any foolproof guides on how to configure Exim 4 and
Cyrus 2.1.x so that they work in harmony?

I just seem to be having a lot of troubles with it. I checked past
archives of exim-users and lo and behold there are plenty of questions
but zero answers. I hope I can get something this time :)

Basically the to-do for my setup are as follows:

* Get mail from outside world to Exim (easy, it does this okay already)
* Get Exim to deliver to Cyrus (any old how)
* Get Cyrus to work (any old how :)
* Get both to use /etc/passwd or so to authenticate both SMTP AUTH and IMAP

The second part is what I'm stuck on now. The third part I'll deal with
when I get to it and probably ask on the Cyrus list too if I can't find
a solution as a result of answers/articles posted in reply to this. The
fourth one is a bind, I have a tiny question about that.

In Exim 3 I tried to make it so that basically you couldn't relay mail
unless you were sending from the local LAN (192.168.0.*) or were
authenticated. Setting it up to authenticate was a NIGHTMARE even
though I read over and over the appropriate section in Phil's lovely
O'Reilly book, and found plenty of online examples (all very different
though.. not encouraging) to work with PAM.

I used Cyrus 1.4.x previously and finally hacked pwcheck to work fine,
and it seems to be working in principle for Cyrus 2.x which means Exim
can just use pam_sasl_pwcheck (or whatever it's called) too - but of
course how?

Thanks for any help or pointers to things I should have already read,
references to pages in the "Exim" O'Reilly or the "Managing IMAP"
O'Reilly gratefully accepted also, just in case I spent hours looking
at the wrong page :P

TIA again
--
Matt Sealey <matt@???>