When you use Outlook's Archive or AutoArchive feature to remove older messages and appointments from your Outlook personal folders or mailbox, the archived messages, appointments, and tasks are moved to the archive.pst.
If you need to look at the messages at a later date, simply open the archive.pst file in your profile and find the message.
Find the Archive.pst
When the archive.pst is not in your profile, you need to open the archive.pst using the File | Open | Open Outlook Data File command in all versions of Outlook. For many users, this command will open directly to the folder where the archive.pst is stored.
If the archive.pst file is not in the folder with your other pst files, you can get the file path from the AutoArchive settings dialog. Open the Tools | Options | Other | AutoArchive dialog and copy the file path.
Additionally, you can open the *.pst file in Outlook 2010 or Outlook 2007 from Account Settings, Data Files tab, or in Outlook 2003 and Outlook 2007 using the File | Data File Management command.
Click Add, then Ok the pst format dialog to open the Create or Open Outlook Data File dialog.
Select the Archive pst file and click Ok to add it to your profile.
Warning: You don't want to use Import and Export command to import your archived items back into Outlook. If you do, you'll have to archive everything again and may end up with duplicates.
Restore archived messages
If you want to move contents of the archive back into your default data file, don't use Import and Export commands. Open the archive.pst in Outlook then select the folders or items and use the Move to Folder command or drag the items to the desired data file.
Using Import or Copy will change the last modified date (in addition to creating copies) while moving will maintain the last modified date. This is important if you want to archive the messages again, since, by default, Outlook uses the last modified date when determining what to archive.
After you have finished working with your archive .pst file, here's how to put it away:
- Display the Folder List if you don't already see it (Folder List button on the navigation pane or Ctrl+6 on your keyboard).
- Right-click the icon for the archive file, then choose Close from the popup menu.
Note that if you copy an archived Personal Folders .pst file to a CD, you will not be able to read it directly from the CD. Outlook requires write access to open a .pst file and you'll need to copy it to your computer hard drive.
Using Outlook's AutoArchive feature
Configuring Outlook's AutoArchive settings tutorial
AutoArchiving by Received Date in Outlook
How to Automatically Cleanup Outlook's Deleted Item and Junk Email Folders
Create an Outlook rule to expire mail after a certain number of days