During peaktime, line utilisation for our network exclusively is around 50 to 60mbps.
Average is around 10mbps
So many terabytes of data passes through our network every month, not sure exactly how much is mail server.
I'd like to remind customers that we route all this bandwidth through quality tier-1 providers (we pay much higher server/network bills) and do not use cogent bandwidth like alot of other hosting providers.