ESEUTIL is a utility to repair, check, and defrag Microsoft exchange stores. Before using ESEUTIL you must unmount your exchange store and be prepared to have downtime.

ESEUTIL /d “C:ExchangeStorePathstore.edb” (Defrag)
Note: I’d rarely recommend using this defrag option, but in certain instances when exchange stores are merged or drastically changed it can be beneficial. This is an OFFLINE defrag and should not be used for frequent maintenance. I’ve seen people make big mistakes by pulling a perfectly good exchange store offline to try and squeeze an extra 10 GB out of it. DO NOT DO THIS! Move the store to another drive or alternative storage.

ESEUTIL /g “C:ExchangeStorePathstore.edb” (Integrity Check)
Run this when you are experiencing problems with corruption in an exchange store. A good example is corrupt messages, having issues exporting mailboxes to PSTs, and general corruption issues. I’ve personally used it for determining if an exchange store was unmounted and shutdown properly before being copied. This is important, because if the store returns a DIRTY SHUTDOWN code, you will not be able to mount it until doing a repair.

ESEUTIL /p “C:ExchangeStorePathstore.edb” /s “C:ExchangeStorePathstreamingfile.stm”(Repair)
Repairs the database to a clean shutdown state. If you don’t have a streaming file, you can create one by using the following syntax: ESEUTIL /p /createstm “C:ExchangeStorePathstore.edb”