Create a new data file and move or copy items to it
On the File menu, point to New, and then click Outlook Data File.
Under Types of storage , click Personal Folders file (.pst) and then click
OK.
In the File name box, type a name for the file, or leave the default, and
then click OK.
In the Name box, type a display name for the .pst folder, or leave the
default.
Select any other options you want, and then click OK. (If you are creating a
..pst file, you can add a password of up to 15 characters. If you select the
Save this password in your password list check box, make a note of the
password in case you need to open the .pst on another computer.)
The name of the folder associated with the data file appears in the Folder
List. To view the Folder List, from the View menu, click Folder List. By
default, the folder will be called Personal Folders .
Drag any item from your current folders to the new folder. Press CTRL while
dragging to copy items instead of moving them.
Notes
You can open a Personal Folders file (.pst) from a network share, but you
must have read/write permissions to do so. Make sure that the .pst is not in
use by another user or program. Otherwise you will not be able to access the
..pst.
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Also:
Reduce the size of a data file
A data file is a Personal Folders file (.pst). If you delete items from a
data file, the size of the file will not change unless you compact the file.
Compacting the file might take several minutes.
On the File menu, click Data File Management.
Click the data file that you want to compact, and then click Settings.
Click Compact Now.
Note When you compact a .pst file, you do not have to exit Outlook.