Import Data to .pst file in Outlook 2010
File
Select File, Open and then Import.
Import and Export Wizard
Select Import from another program or file and click Next.
Import a file
Select Outlook Data file (.pst) and click Next.
Import Outlook Data file
Select Browse.
Open Outlook Data File
Select the file you would like to import and click Open.
Import Outlook Data File
You will see the file and the path listed. Choose do not import duplicates and click Next.
Import Outlook Data file
If you would like to import all the folders from the .pst file make sure the top level folder and include subfolders is selected. Choose the mailbox you would like the data to go into and choose Finish.
Outlook will import the .pst file to the location set previously. Once complete, Outlook will begin to push the restored file(s) to the Exchange server. If Outlook lags during this time, keep Outlook open and use Outlook Web Access until all data has been uploaded to the server.