[exim] Oulook 2003: no message ID

Hi

I have exim 4.50 server that posts emails to a newsgroup server (innd) via
mailpost. However when Outlook 2003 users email to the newsgroup it is
rejected
with the reason "no Message-ID: found".

I have now seen that outlook 2003 does not include message ID's unless
sent via an
Exchange server. Can I config Exim somehow to get round this? or can
anyone advise
a look around for this?

Thanks

Jamie