[exim] no message ID - newsgroup posting problem

Hi

I don't think this is a exim issue, but wondering if anyone else has
seen this
problem.

I have exim 4.50 server that posts emails to a newsgroup server (innd) via
mailpost. However when Outlook users email to the newsgroup it is rejected
with the reason "no Message-ID: found". I can't see any option in the
innd conf
files to stop this.

Thanks

Jamie