Compact Outlook OST File

Click File in the top left corner of Outlook.


Click Account Settings button and then select Accounts Settings... from the drop down menu.


On the Data Files tab, select your email address from the list, and then click Settings.


Under the Advanced tab, click Outlook Data File Settings button. Click Compact Now button and then when it has finished, select OK button to back out of the settings menu.

NoteIt can take a few minutes for Outlook to finish compacting action!