Open Outlook and ensure that the PST file you want to import is not already in use. You can do this by right-clicking your PST file’s name in your folder list and choosing Close “.pst”
For confirmation you may wish to exit Outlook and then relaunch it to assure that the PST files are free from any connections from the client.
Select and click on a destination folder for your PST file’s content. (NOTE: this is the folder the mail will be imported into).
At the top of your Outlook 2016 or 2013 ribbon, choose File.
Choose Open & Export and then Import/Export.
Select “Import from another program or file” and click Next.
Select “Outlook Data File (.pst)” and click Next.
Browse to your .pst file, select it, and click Open.
Choose whether you want to allow, replace, or not allow duplicate items. Then click Next.
If you want to import the entire .pst file, select the main folder containing all subfolders. Then select the checkbox labelled “Include subfolders”
You can Expand the Outlook Data File until you see a specific folder with the emails you want to import, Select that folder. Then select the checkbox labelled “Include subfolders”
Finally, select the option labelled “Import items into the current folder” and click Finish.
The emails and folders will appear in your currently selected folder. If you need to make any final adjustments, simply drag and drop the emails and folders to the correct location.