Compacting your Zimbra ZDB profile allows you to save disk space by compressing your profile information and settings.
Here are the steps for accomplishing this:
1. Within Outlook, select File —> Data File Management:
2. In the Account Settings dialog, click the Data Files tab:
3. Select the Zimbra profile for which you want to compact the ZDB and click Settings, or double-click on the profile to compact:
4. In the Zimbra Server Configuration Settings dialog, select the ZDB Configuration tab and then click Compact ZDB:
5. A progress window opens:
When the window closes, the ZDB compaction is finished and you can click OK.