How to Password-Protect Outlook PST Files

This article explains what a PST file is and how to password-protect Outlook PST files. Instructions apply to Outlook for Microsoft 365, Outlook 2019, Outlook 2016, Outlook 2013, and Outlook 2010.

Password-Protect Access to an Outlook PST File

To apply a password to an Outlook PST file:

1. Open Outlook.

2. On the File tab, choose Account Settings > Account Settings.

3. Select the Data Files tab.

4. Choose the Outlook Data File (.pst) for which you want to create or change a password, and then choose Settings.

5. Select Change Password.

   If you have an Exchange account, the Change Password button won't appear. Your network password is your .pst password.

6. In the New password and Verify password boxes, type a password of 15 characters or less.

   Remember your password! Microsoft can't retrieve it for you if you lose it. Write it down and keep it in a secure location.

7. Select OK to save the new password. You've successfully password-protected the PST file.

What is a PST File?

The Microsoft Outlook email program stores your messages and other Outlook files on your computer in the form of Outlook Data Files with the extension .pst. These files are commonly referred to as PST files.

Outlook lets you password-protect PST files to prevent other users from unintentionally altering, deleting, or otherwise accessing these potentially sensitive files on a shared computer.