[exim] Sender/Return-Path with autenticated users

Hi all,

How do I stop Exim adding or "munging" Sender and Return-Paths for
authenticated users?

My understanding of chapter 44 section 1 (44.1) is that if I leave
out control = submission or set control = submission/sender_retain
for a RCPT acl, thus:

  accept  authenticated = *
#          control       = submission/sender_retain
# (note the hashed out control line)

or

  accept  authenticated = *
          control       = submission/sender_retain

That Exim will leave my Sender and Return-Paths alone (I'm assuming
the former will not set Return-Path and Sender if they are not
present as it is treated as "remote" and not a local submission
and the latter will add them, but use my From details).

However on authenticating with either the control = submission OR
with control = submission/sender_retain set, Exim seems to set up
both Return-Path/Sender to a "munged value" based on my authentication
details.

Note I set the from as "postmaster@???" but Exim
rewrites this to my authenticated sender "dravtest" and the domain
is set to the hostname of the mailserver (smtp.bis-internet.co.uk)
(as I have no qualify_domain setting). Any idea's how I can get it
to set these as the original From sent by the submitting MUA?


Headers in received email:

Date: Wed, 21 Feb 2007 03:03:41 +0000
From: postmaster@???
Subject: test Wed, 21 Feb 2007 03:03:41 +0000
Sender: dravtest@???
To: dsloan@???
Message-id: <E1HJhmD-0001to-3i@???>
Return-Path: dravtest@???



Regards

Drav.