Question: How to compact the database, reduce the size? Answer: Usually, databases never decrease their sizes during the normal operations. Typically, exchange database will grow for several months, and eventually stabilized. There are two methods to reduce the database size: Offline defragmentation; Move mailboxes into another newly created database Before start the task, please confirm if you have enough free space to be freed. The event 1221 after the online maintenance will tell the information. More information: How to defragment with the Eseutil utility Eseutil /D Defragmentation Mode