If you need to merge multiple PST files and want to merge them into a single PST file . In this way, you can merge PST files into new PST, existing PST or Outlook Profile. It also helping the user to combine Outlook archives, password-protected, active, and network files.
Start and run Microsoft Outlook and then go to File >> Open >> Import option.
The Import/Export wizard opens up next. Select the option to import from another program or file option and click on the Next button.
Select the option Outlook Data File to import that file type.
Click on the Next button.
Click on the browse button in order to select the file to import.
Then in the next step, you will get the option to not import duplicates to eliminate the possibility of the removal of duplicate items. Click on the Next button.
Select the folder that you wish to import.
Check on the include sub-folder and import items into the same folder in options.
Finally, click on the Finish button.