I have seen a slew of posts about this. My question is as follows.
There are two ways two migrate mailboxes ... interorganizational (setup Exchange 2003 as a new organization than that of Exchange 5.5) and using the ADC with Exchange 2003 in the same organization as Exchange 5.5. My site had no public folders.
Someone correct me if I'm wrong. If I install with the ADC, then I can migrate users and nothing should happen connection wise during this process? Then, once I have migrated users, I can remove the Exchange 5.5 box.
Now, if I setup Exchange in a new organization and migrate users using Exchange Migration tool (remember, no public folders) should I not also be able to migrate users, and while the Exchange 5.5 box is still in place, nothing happens to their connection.
My ultimate goal is little to no downtime of users mailboxes if possible. MS recommends the ADC, but I was wondering if anyone actually had war stories related to this problem.