You can copy messages and other items into a new or existing set of personal (.pst) folders. This option lets you select which items you want to export and which you want to exclude. You can use this method whether your mail is stored in a hosted Exchange Server mailbox or in a set of personal folders.
To create a .pst file of your Mailbox and all of its folders:
- In Outlook go to File > Open > Import

- Select Export to a File and choose next.

- Select Outlook Data File (.pst); click next.

- Highlight "Mailbox-Your Name" to export the entire contents of your mailbox. If you want to backup only a selected subfolder such as your Calendar, highlight only the Calendar folder.
- Check "Include Subfolders" if you have subfolders you want to backup as well. Do not check "Include Subfolders" if there are no subfolders required for the backup.

- Click Next.
- In the "Save Exported File as:" field use the Browse button to select the location and file name of this .pst file. (It is recommended to save the file to a location that is familiar to you.)
8. Select "Replace Duplicates with Items Exported".
9. Click Finish. Then click Ok on the next screen. (You do not have to enter a password.) All data will now be exported to the .PST file. You can save this file as a backup or use it to import into a new Outlook profile.