Error Solved: OST cannot be Accessed Configured Different Mailbox

Outlook error “OST cannot be accessed because it has been configured for use with different mailbox” occurs when you try to access an OST file on a system on which the file is not originally created or in case there is a server synchronization issue. However, to understand this error in detail, a brief introduction to Outlook OST file is essential.

Pro Tip: You can fix “OST cannot be accessed.” error instantly by using Stellar Converter for OST. Use the software to convert OST to PST in a few simple steps, and import the PST into Outlook directly.

Outlook OST – An Overview

As you may already know, Microsoft Outlook can be configured with an IMAP or Exchange server. When a user sends/receives data through IMAP or Exchange server configured Outlook account, and update emails, contacts, calendar or journal entries, the data is directly saved on the server. However, a synchronized copy of this data is also saved on the local computer in an Offline Storage Table file or OST. This Outlook data file (OST) allows the user to access the mailbox, even if they aren’t connected to the mail server. The changes made to the local data file (OST) are automatically synchronized with the server mailbox, when Outlook reconnects with the server.

Additional information about the OST file:

• While all the emails that you send and receive are saved on the server, you can choose to save emails, calendars, contacts, tasks, and other folders only on your local system by explicitly setting them as “Local only”.
• By default, OST files are stored in Users\user\AppData\Local\Microsoft\Outlook.

The Problem with OST Files

When you change the work system, one of the most important things you need to transfer is your important Outlook mailbox items. This raises a problem because while most emails that reside on the Exchange server can be easily accessed on any other machine with OWA, the items that are saved only on the local machine (by using the “Local Only” setting) in the OST file cannot be accessed. You can recreate the OST file on another machine by connecting to the online mailbox in Outlook, but you can’t access the offline and unsynchronized mailbox items that exist in the old OST file.

Refer to this article to learn how to transfer Outlook data to new machine.

To access such mailbox items, you need to convert the OST file to PST as PST files can easily be transferred from one machine to another and opened directly with Outlook. However, you can’t do the same with OST files. This is one of the main reasons why you need to perform Outlook OST file to PST conversion to access your old data saved in OST.

“OST Cannot be Accessed” Error

One of the errors Outlook generates if a user tries to open an OST file on a different machine is:

“OST cannot be accessed because it has been configured for use with a different mailbox.”

The reasons why this error occurs may vary. For instance, you can face the error if you upgrade your Outlook software, or create a new Outlook account and try to access an old OST file from the previous account (orphaned OST).

If you are facing OST cannot be accessed error, you can try the following fixes:

• Login with the old username that you used at the time of the OST file’s creation. It should be a cached login. If you are able to launch Outlook, you can export the OST data to PST format.
• Login as Administrator to take “ownership” of the OST file and then try to access the OST data.
• Request your Exchange Administrator to manually export the required items from your old server mailbox.

What if Common Fixes Don’t Work?

If none of the above-mentioned fixes work or you need to access the OST file on a different machine, converting the file into PST would be the best course of action. We recommend using Stellar Converter for OST software to perform the conversion because of its impressive features, such as:

• Converts encrypted OST files
• Shows free preview of OST file data after conversion
• Supports almost every Outlook version including 2019, 2016, 2013, 2010, and older versions
• Converts even large OST files to PST in a short period
• Converts multiple OST files to PST in a single batch process (Technician Edition)

This software performs risk-free conversion of all items stored within an OST file and allows you to save the converted file in multiple formats such as PST, MSG, RTF, EML PDF, etc. You can also use the software’s demo version to convert up to 20 emails per folder for free.

Stellar Converter for OST software can come in handy not only in the scenario discussed above, but also if you’re dealing with an orphaned and inaccessible OST file. You will be able to extract all your important data from multiple OST files and save it in PST format with the help of this tool.

Software Recommendation by Top Editors:

So, why look elsewhere?

If you’re having trouble in accessing the data in Outlook OST files, you can convert the files into PST swiftly and smoothly with Stellar Converter for OST. You’ll end up saving a lot of time and effort.

Software Video Tutorial

Check our MVP review to get learn more about OST to PST Converter from Stellar.

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About The Author

Shivom Sharma

Translating tech talk into everyday language—because everyone deserves to understand their software.