[Exim] exim to cyrus deliver: Message contains invalid heade…

Hello,

I'm using exim 4.10 and want to deliver mail locally
to a cyrus version 2.1.9 imapd. I'm trying to use
normal (pipe) delivery with /usr/sbin/cyrdeliver aka
'cyrus deliver' programm (no lmtp). (This is a debian
system. In the normal case the program is just called
'deliver'

The cyrdeliver always complains about

> Message contains invalid header

Further investigation reveals that exim what to deliver
a file like this:

1 > From name@??? Mon Nov 18 31:33:09 2002
2 > Return-path: name@???
3 > Received: [...]
4 > To: [...]
5 > Subject: [...]
6 > Body of message

A message of this kind is _always_ rejected by cyrdeliver. The
problem is line 1 (the envelope???).

Is there any option to suppress line 1 when doing local delivery?

Cheers,

Thomas

PS:
Tried lmtp over tcp on port 2003 as well. In this case my problem
is to authenticate against cyrus. Even after reading the corresponding
part of the manual/specification, I've got problems to use plaintext
authentication in exim. Perhaps there is alse somebody out there who
knows how to do and can post the relevant part of the exim configuration
as well...