For this part of our Groupwise to Google migration, we are trying to make sure we can move our 3 Groupwise Post offices (total of ~1,500 users) Inboxes in a "reasonable" amount of time. We are aiming for a cutover during Spring Break, so I have about 10 days to move mailboxes. I will try to baseline the speed this weekend or next by running about 30 mailboxes per server. Right now, the pipe is only about 6Mbps, but are testing a setup that will get us up to 100Mpbs out to Google. Seriously hoping the 100 works out.