How to Change an OST File Name in an Version of Outloo?

OST to PST Converter /May 20, 2026

Are you trying to figure out how to rename an OST file? Or would you like to know why renaming an OST file could be required? In this article, we will address a number of variables and situations. You will also gain additional knowledge about the OST file and its applications.

What is an OST file in Outlook?

Users of Outlook are aware that an OST file, which is produced when Cached Exchange Mode is enabled, is a local copy of their Outlook mailbox. Offline Storage Table, or OST, enables users to read, write, and open emails even when they are not connected to the internet. The OST file immediately synchronizes with the Exchange Server, Microsoft 365, or IMAP account when the user reconnects.

While OST files provide constant mailbox data synchronization with the server, Outlook also uses PST files to store data locally without server synchronization.

When do we need to rename OST file?

There are other reasons to rename an OST file than re-syncing data. Renaming the OST file can also be useful in a number of other circumstances, including:

  • The Outlook profile won’t load.
  • Even when you are online, the OST file is not synchronizing with the server.
  • The OST file is damaged or corrupted.
  • Outlook displays the “Disconnected” state.
  • Outlook operates slowly.
  • One Outlook profile is associated with several OST files.

You can rename the OST file and let Outlook download a fresh copy from the server if you run into any of these problems. This procedure frequently aids in fixing synchronization issues and local faults.

Is renaming the OST file safe?

Yes, unless your mailbox is accessible on the server (Exchange, Microsoft 365, or IMAP), it is completely protected. Outlook will just build a new OST file the next time you access it since all of your mailbox data is stored on the server.

NOTE: Because it doesn’t resync with the server, this doesn’t work with POP accounts.

Step 1 – Shut down Outlook

Shut off Microsoft entirely, even if it’s operating in the background.

Step 2 – Locate the OST file

Location of the OST file (by default)

C:\Users\%username%\AppData\Local\Microsoft\Outlook\
ost location

Additionally, you can open “appdata” directly by using the “Run” command.

Note: Enable hidden items if you are manually browsing and the AppData folder is not visible.

Step 3 –  Select the appropriate OST file

This is the most common step in selecting the right OST file. Select the appropriate account or profile if you have several. You can use account settings to examine the location of Outlook data files for that.

Step 4 -Rename the OST file

After locating the file, right-click on it and choose Rename. For instance, user_address.ost to user_address_backup.ost

rename ost

Step 5 – Restart Outlook

Now open Outlook to resync all of your inbox items and build a new OST file.

Final Decision

Unless there is a problem, renaming the OST file is not necessary. Users can create a new OST file from the server by following this step-by-step instructions. Use caution while following these instructions with a POP3 account, as this could lead to data loss. Before starting the renaming process, it is also advised to make a backup or export the OST file to a PST file.

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