Outlook PST file will become large after being used for some time. Actually it is possible to reduce its size by compact or compress it. There are two ways to do that:
1. Using “Compact” Feature in Outlook:
This is the official way to compact a large PST file, as follows(Outlook 2010):
- Click the File tab.
- Click Account Settings, and then click Account Settings.
- On the Data Files tab, click the data file that you want to compact, and then click Settings.
- Click Compact Now.
- Then Outlook will start compact the PST file.
This is the steps for Outlook 2010. For other Outlook versions, there are similar functions. The official “Compact” operation will eliminate the spaces used by permanent-deleted items and other unused items. However, this method is very slow when the PST file is large.
2. Compact the PST file manually:
Actually you can compact a PST file manually by yourself, as follows:
- Create a new PST file.
- Copy all the contents in the original PST file to the new PST file.
- After the copy operation, the new PST file will be a compacted version of the original PST file, since the permanent-deleted items and other unused items will not be copied.
Based on our test, the second method is much more faster than method 1, especially when the PST file size is large. So we recommend you to use this method to compact your large PST files.