Tommy,
> We would like to be able to archive internal email (from user to
> user within our domain) messages to the exim server as well but
> haven't quite figured out how to accomplish that with Exchange.
> I am wondering if there is a way to have Exchange replicate all
> internal messages passing them to the exim server for archiving.
Have a look at
http://www.mintercept.com/ MailIntercept can teach
Exchange to route all internal Mails through an external SMTP service. I
evaled it years ago and it worked nicely. However depending on what you
want to achieve a professional mail archiving solution might be a better
way. One cheap but good solution for Exchange is
exclaimer mail archiver
http://www.seceidos.de/de/produkte/technologien-und-loesungen/exclaimer/
mail-archiver/
http://www.exclaimer.com/mailarchiver.aspx?
Contact me off list if you need more info.
Regards,
JP