Routed mails to internal servers & totals of

Does anyone know how to get the total numbers of mails transferred on a particular day to internal sources from internal sources. IE a mail sent from me to the bloke sat next to me, I do not need to know what was sent / received externally just from server to server within the same domain?

I have used reports.nsf - but I presume message volume section will include received as well as sent via that particualr server no matter what the source.