If I understand correctly, you don't need to plan bandwidth for
web browsing, as that goes through the dial-in provider, but
you do need to plan for smtp bandwidth, as that's in-house?
I'm reading page 33 of the Jan 31, 2000 Netword World magazine,
which has an article quoting stats from Ferris Research:
User messaging will jump 81% to 34 messages -received- per user per day.
Message size will jump 192% to 286KB per message.
If you take that at face value, you need to be able to handle
(286KB * 8) * 34 * 10,000 (or whatever you said), divided by
36000 seconds in 10 hours, gets you ... 21Kb/sec? Assuming
every user also sends you that traffic as a smarthost in that
same time period means you need... 63Kb/sec line?
And you have a 2meg line spec'd currently? :)
This all changes if you need bandwidth for web traffic, of course.
John