How to open an Outlook PST Data File
Select File > Open & Export > Open Outlook Data File.
Note: Depending on how Outlook is set up, it's likely the folder where the .pst file is stored will open automatically. If it doesn't, browse to the file's location. If you're not sure where your Outlook data file is located, see Locating the Outlook data files.
Select the Outlook Data File (.pst), and then select Open.
Once you open the Outlook Data File (.pst), the file will appear in your folder pane. Usually you'll find it at the bottom of the list of folders. The following image is an example. The name of your Outlook Data File (.pst) will likely not be outlook data file. Usually, the name is based on the account the file is associated with. For example, an Outlook Data File for the account Name.Surname35@domain.com will likely be named Name Surname or Name.Surname35@domain.com.
How to close an Outlook PST Data File
You can remove an Outlook data file from the Folder pane by closing the file. This does not, however, remove the file from your computer.
In the Folder pane, right-click the name of the Outlook Data File, and then choose Close "Outlook Data File".