0 Speed up Exchange 2010 mailbox migration

Exchange 2010, by default migrate mailboxes in two streams.
So you can migrate only ~4Gb an hour.

To speed up this process , you can edit MSExchangeMailboxReplication.exe.config 
File is located in :  C:\Program Files\Microsoft\Exchange Server\V14\Bin

Find the following values:

MaxActiveMovesPerSourceMDB = “5″    
MaxActiveMovesPerTargetMDB = “2″    
MaxActiveMovesPerSourceServer = “50″    
MaxActiveMovesPerTargetServer = “5″    
MaxTotalMovesPerMRS = “100″

Change values to:

MaxActiveMovesPerSourceMDB = “6″    
MaxActiveMovesPerTargetMDB = “6″    
MaxActiveMovesPerSourceServer = “50″    
MaxActiveMovesPerTargetServer = “40″    
MaxTotalMovesPerMRS = “250″

After editing and saving you must restart Microsoft Exchange Replication Service.

Note : This speed up is relaying on your hardware. 
So you have to be sure , that your server can handle more streams.

Source : LINK