Event ID 1221 - Exchange Defrag free white space
You may see event ID 1221 in your Exchange Server logs. This event is generated by the Database maintenance defragmentation process.
The Exchange Mailbox database is defragmented to clear any free "white" space in the database which may have been generated by deletion of mailboxes, or just email inside mailboxes. The overall database size will NOT reduce but it will mean additional data can be added to the DB without its physical size growing.
The details of Event ID 1221 will show how much white space has been achieved during the defrag process. This confirms the space available inside the database. Sometimes the amount can be inaccurate, so if you think it is wrong you can run the following command on the DB to get a more accurate result:
eseutil /d
The output of this command will give you an accurate view of the current DB usage and available white space.








