It’s possible you may encounter a move error when migrating Exchange 5.5 mailboxes to an Exchange Server 2003 storage group. In fact, several presenters on my team hit this error in front of live audiences last week. Considering the session we were delivering is an Exchange 5.5 to Exchange Server 2003 Migration seminar, this could be pretty embarrassing.
So what happened and how do you fix it? Fortunately, the problem we encountered in our content was documented nicely in KB article 886700. Since our content is in a Mixed Exchange environment we hit the MAPI logon failure.
There are two methods suggested as fixes in the KB article. The first is to perform the move from an administrative workstation that is not the Exchange server. Having a workstation on the network with the server admin tools is a likely scenario for most organizations.
For our content, we simply applied Exchange Server 2003 SP1 immediately after the install of Exchange Server 2003. That fixed the problem, too. We liked the SP1 fix because it meant we didn’t need to build another Virtual PC VM with the admin tools for NT4, Exchange 5.5, Windows Server 2003 and Exchange Server 2003. I’ll probably do it anyway in my spare time... J