We recommend that all .pst files be imported/moved into Office 365.  The 100GB quota in Office 365 provides ample storage for email and all of your email is kept in one place. See Moving Email From a .pst File To Your Office 365 Account for more information.


Outlook allows you to create Outlook Data Files (personal folders or .pst files) to give you additional storage capability.  With the quotas available in Office 365, you probably won't need to create a .pst unless it is for archiving purposes.  

The Personal Folders or .pst files can be stored locally on your hard drive or if you are creating the .pst file for archiving purposes only, it could be stored in a network share such as OneDrive.  OneDrive cannot be used if you are using the .pst file everyday -- it will not be able to be backed up. If you store them on your hard drive, you MUST back it up on a regular basis.  NOTE:  Microsoft does not support .pst files being stored on a network share such as OneDrive.

If you are moving to a new computer and your personal folders are stored locally, you will need to move them into Office 365 or save them to a network drive or external storage device before you make the switch.  If you need to open a .pst file that you have stored on OneDrive, you should move it to your hard drive first and then open it otherwise, it may get corrupted.

  1. Choose File | Account Settings | Account Settings | Data Files
  2. Click Add
  3. Choose the location to save your file on the "Create or Open Outlook Data file" prompt. This can be your local hard drive (C: drive) or a location on a network share (not recommended). The default location is C:\Documents and Settings\Local Settings\Application Data\Microsoft\Outlook. The default file name is: My Outlook Data File(1).pst
    NOTE: ITS recommends that you first create a folder outside of the default Outlook directory to save your .pst files (e.g., C:\Outlook Files). This is important to easily locate your .pst files and is especially important if you move to a new computer and need to move a Windows profile
    NOTE:  Microsoft does not support .pst files being stored on a network share
  4. Click OK.
  5. Select the new .pst file then click Settings... to modify the Outlook Data File name or set the password.  
  6. Click OK. The .pst folder is now created. There are two default folders in your new .pst folder -- Deleted Items and Search Folders. You can now create new folders for storing mail.
  1. Right click on the .pst folder name and choose New Folder.
  2. Type the folder name and select the location (your .pst folder).
  3. Click OK.
    Once you have created folders for storing mail you can move messages to those folders. 
  1. Right click on the message you wish to move.
  2. Choose Move to Folder
  3. Select the folder name (.pst folder) and click OK.
  1. Choose File | Move to folder or click the Move to Folder icon
  2. Choose the folder name from the list of recently used folders or click Move to Folder
  3. Select the folder name (.pst folder) and click OK.

Additional Information

 When you delete items from a Personal Folders file, your file size will not decrease until you compact the file.

  1. Choose File | Account Settings | Account Settings  | Data Files
  2. Click the .pst file 
  3. Click Settings
  4. Click Compact Now.
  1. Right click on the .pst file name.
  2. Choose Properties.
  3. Click the Advanced tab. 
  4. In the Name field, change the name of the .pst file. 
  5. Click OK to save the changes. 

If you already have personal folders and you want to find out where they are stored:

  1. Right click on the folder name. 
  2. Choose Properties.
  3. On the General tab, click on the Advanced button.
  4. The location of the personal folders is listed under the Filename field. 

NOTE:  Microsoft does not support storing personal folders on a network drive or OneDrive, they recommend storing on your hard drive which you will need to backup.

There are several methods to choose from for backing up your PST files:

  1. A Microsoft utility that enables you to make a .pst data file using Outlook. For more information on creating PST backups with Outlook, see "Back up your email".
  2. Use Microsoft Windows backup utility. A backup wizard will prompt you for: which files to backup, where to back them up (e.g., H: drive, external drive, etc.), and how often to back them up. Manually backup the files by copying the files to your H: drive or external drive

NOTE: ITS provides limited support for these methods.

You first need to create a rule to put a copy of the messages you send into the "Sent Items" folder in the .pst file.

  1. Choose Tools | Rules and Alerts.
  2. Click the New Rule button.
  3. Click Start Blank Rule.
  4. Click Check messages after sending and click Next.
  5. Check "through the specified account".
  6. Click "specified" and choose the account this rule applies to (e.g, Microsoft Exchange Server) and click OK.
  7. Check "Move a copy to the specified folder".
  8. Click "specified" and choose the folder to copy the messages (e.g, your Sent Mail folder in a .pst file) and click OK.
  9. Click Finish.

Next, you need to change your options so that a copy of the message is not saved in your "Sent Mail" folder on the Office 365 server.

  1. Choose Tools | Options | Email Options.
  2. Deselect "Save copies of messages in Sent Items folder".
  3. Click OK.
  4. Click OK on the client-rule message.
  5. Click OK.

If Outlook cannot open because the Personal Folder.pst file is damaged, and it says to run the Scanpst.exe tool after closing Outlook, then run the program according to these directions: http://support.microsoft.com/kb/272227

When the tool opens, copy the file path to the Personal Folder.pst file in the appropriate box and press start.  The program will run and then prompt you to to repair the file.  After the program is done, open Outlook to confirm that the repair was successful.

If you need to export email to a .pst file for archival purposes, you should export the data using steps below and then close the .pst file.  Do not keep the .pst file open in Outlook.  At a later date, if you need to open the .pst file, you should first move it to your hard drive and then open it.  Be sure to close it before moving it or backing it up again. 

  1. In Outlook, choose File
  2. Choose Open & Export
  3. Choose Import/Export
  4. Choose Export to a file and choose Next 
  5. Choose Outlook Data File (.pst) and choose Next
  6. Select ‘All’ and select ‘include subfolders’  and choose Next
  7. Name the file and note the location
  8. Choose Finish
  1. In Outlook, choose File
  2. Choose Open & Export
  3. Choose Import/Export
  4. Choose Import from another program or file and choose Next
  5. Choose Outlook Data File (.pst) and choose Next
  6. Browse to find the 'File to import' and choose Next
  7. Select the 'folder to import from' and choose 'Include subfolders'
  8. Select Finish
Article number: 
Last updated: 
December 23, 2020