A password can be set for an Outlook Data File (.pst) to help prevent unplanned interruption by other people who share your computer, such as members of your family. When a password is used, a password prompt appears when Outlook starts or when the file is first opened within an Outlook session.
To set the Outlook account password, right-click on the account name in the left corner and select Data File Properties.
Now, the Personal Properties window appears at your screen. In General tab, click on Advanced.
The Outlook Data File screen opens. Click on Change Password button.
Set new password, the password can be 15 characters long and case sensitive. In verify password tab, retype the new password again.
Also if you don’t want to enter a password each time visiting your account, tick the Save this password in your password list. However, if you share a computer with others, don’t select the Save this password in your password list check box because they may access to data file on your Outlook.
You should create a strong password that combine uppercase and lowercase letters, numbers, and symbols to ensure the safety of your Outlook data files.
Do not use birthdays to make the password for someone can easily guess out.
After entering your password, click on OK twice to close the Outlook Data File dialog box.
Finally click OK to close the Personal Properties window.
From now, when you opens Outlook, Outlook Data File Password will display on notifications screen, then enter your password to access your Outlook account.
If you want to change or remove the password, follow the same steps to access the Change Password dialog box. Enter your current password into the Old Password field.
To delete your password, leave the New password and Verify password field blank.
Above are some simple steps to set a password to protect your Outlook data file. Goodluck!