[Exim] watching exim (was lost e-mails founded)

Hello,

it is a unfavourable situation.
We lose a couple of messages per month and I can't keep track,
cause there are no journalisation for those messages.
The only thing I see are the abandoned data files (-D) at the
"input" directory.

Therfore I would like to run our main mailsystem at debug mode
for a few days to get more information.
But exim writes all his debug output to standard error
consequently he can't demonize.

Is it possible to write exims debug output straightly to the syslogs or a
certain file ?

regards
Oliver