Migrating Exchange Mailboxes from Exchange 2003 to Exchange 2010

After adding an Exchange 2010 server to my lab, I wanted to shut down my Exchange 2003 server.  Before I could do that, though, I needed to migrate the Exchange 2003 mailboxes to the new 2010 database.  Fortunately, this can be done from the EMC on the 2010 server.

Unfortunately, after I tried to migrate one of the mailboxes, I noticed that the process was failing after a couple of minutes.  I fired up the handy dandy Exchange 2010 Powershell prompt and used the command "get-moverequeststatistics -id <mailbox name>.  It showed me that it was failing at 95% completion due to a problem with msExchVersion.

I fired up ADSI Edit and located msExchVersion in the schema for that particular user.  Sure enough, it was null.  I guess the migration process was expecting some value there and failing because the field was empty.  I looked at that field on a user I had added an Exchange 2010 mailbox for and just copied the value for msExchVersion to each of my old 2003 mailbox users.  After doing that the migration worked without a hitch.

I'm sure there must be some way to correct this in one fell swoop, but since I didn't have that many accounts, I chose to just add the value to each user manually.  This would have been a pain in a large organization, though.