While I was at a customer site, I was asked whether it is possible to make Exchange 2010 store more history of the mailbox moves.
The answer is yes and it is easy to implement. By default, Exchange 2010 only stores history of two moves performed on a mailbox. The mailbox moves are performed by Mailbox Replication Service (MRS) and hence the config file for this service has to be edited to change the number of mailbox move history.
Navigate to the \Bin directory on the CAS server and open the MSExchangeMailboxReplication.Exe.Config file using notepad. Edit the MaxMoveHistoryLength with a value between zero and hundred. Save the file and restart the MRS service.
If you have more than one CAS server, the above steps have to be repeated on all of them as the config settings are per server.