Outlook 365's OST files let users interact with their mailbox data even when they aren't connected to the internet. But system failures, unexpected shutdowns, or synchronisation issues may harm these files. When this occurs, you may not be able to get to your mailbox contents, which might mess with your everyday activities and productivity. This problem might be particularly hard for those who use Outlook for work to talk to each other and plan their days.

Fixing a damaged OST file is frequently the only way to get back into your email data. Outlook has several built-in repair methods, however they typically don't work when the OST file is badly damaged or orphaned. In these situations, the OST to PST Converter is useful since it can get data out of broken OST files and turn it into PST format. This keeps the mailbox accessible in Outlook while keeping the original folder structure and data formatting.

Learn how to fix a broken OST file by hand, which will let you have full access to your Outlook 365 mailbox again.

What is the use of an OST file?

Outlook syncs the data in the OST file with the Exchange Server while you are online. This makes sure you always have the most up-to-date information. This synchronisation happens automatically and without any effort on your part, so you may work online and offline without any problems. You may also toggle on or off Cached Exchange mode in Outlook to enable the OST file.

What problems can corrupted OST files cause?

If your OST file is corrupted, it might be a big problem since you won't be able to get to your mailbox data. Some of the most typical reasons for OST file corruption include abrupt power outages, virus or malware assaults, closing Outlook incorrectly, and the file being too big. If an OST file becomes damaged, you could have a number of problems, such as:

• Not being able to open an OST file in Outlook 365 and get to the mailbox data
• When trying to sync the OST file with the Exchange Server, you get error warnings.
• Outlook can't open the data file, which makes it freeze or shut without warning.
• Mailbox data that isn't complete because some emails are missing or have been destroyed.
• Outlook runs slowly or freezes when you try to open the OST file.

What does an OST file go corrupt?

There are a number of things that may make an OST file corrupt. Some of the most prevalent reasons are:

• A sudden loss of power is one of the most common reasons why OST files are corrupted. If the computer shuts down unexpectedly when Outlook is open or while it's syncing the OST file with the Exchange Server, the OST file might be damaged.
• Viruses and malware may attack your system and do a lot of harm. They usually corrupt or delete vital data files, such OST files. If these bad programs get into your computer, they might mess with the way files are organised, which could make it hard or impossible for Outlook to access to your mailbox data.
• How to Close Outlook the Wrong Way: Closing Outlook the incorrect manner, as by forcing it to stop or crashing the computer, might harm OST data. Learn how to save Outlook emails on a hard drive that is not your computer.
• Large OST File Size: As an OST file becomes larger, it is more likely to get corrupted since it is harder to work with and takes more system resources. Files that are larger are more likely to crash and cause issues, especially on older computers or systems with limited resources. The simplest way to decrease this risk is to change the OST file into smaller PST files that are simpler to deal with.
• Issues in getting on the network: Outlook 365 won't be able to sync emails if there are network difficulties that stop it from connecting to the Exchange server. These types of connection issues might harm the OST file.
• Outlook Software Issues: If there are difficulties with the Outlook software itself, such bugs, old versions, or conflicts with other applications, OST files might get damaged. If Outlook is refreshing the inbox but not receiving any new emails, it might be because the add-ins you have don't function with the version of Outlook you have.
• Issues with the storage device: If the storage device where the OST file is kept has issues, such a hard drive failure, the OST file could be messed up.
• Deleting or moving files that are connected to the OST file by accident, or modifying the OST file outside of Outlook, might lead to corruption. Find out how to fix the problem that says "Outlook data file cannot be accessed."

How to mend and repair an OST file that is broken?

You may use a built-in tool like ScanPST.exe or a third-party program like OST to PST converter to fix a damaged OST file. If the corruption is severe or the built-in tools can't fix the OST file, the utility can assist you fully recover and fix the OST file so that you can use it again.

Here are various ways to fix corrupted Outlook data files.

Use the Inbox Repair program (ScanPST.exe) as the first step.

The Inbox Repair tool that comes with Microsoft Outlook may assist fix PST and OST files that are broken. Follow these procedures to fix a corrupted OST file using the Inbox Repair tool:

Step 1: Shut down Outlook and any other programs that are connected to it.
Make sure that Microsoft Outlook is not open and that there are no Outlook processes operating in the background.

Step 2: Look for the ScanPST.exe application on your PC.

• Microsoft Outlook has a built-in repair tool called ScanPST.exe.
• Depending on the version of Outlook you have, ScanPST.exe may be in a different place. You can generally find it in the folder where Office is installed, however.
• The default location for this file is C:\Program Files\Microsoft Office\OfficeXX\ScanPST.exe.

Step 3: Use the ScanPST.exe program to fix the OST

• To launch ScanPST.exe, double-click on it.
• Click "Browse" and choose the OST file that has to be fixed.
• To start the scan, click "Start."
• The ScanPST.exe application will look at the OST file and try to fix any problems it discovers.
• The program looks through the OST file and gives a summary of what it found.
• To fix the problems, click "Repair."
• You may open Microsoft Outlook again when the repair is done and see whether you can get to your mailbox data.

Step 2: Convert the settings on your Outlook profile to create a new OST file.

You may try making a fresh OST file if the first technique didn't work. To create a new OST file, follow these steps:

Step 1: Close Microsoft Outlook and any other programs that are linked to it.

• Click "File" and then "Exit."
• Make sure that Microsoft Outlook is not open and that there are no Outlook processes operating in the background.

Step 2: Give the corrupted OST file a new name

• To find the corrupted OST file, proceed to "File," then "Account Settings," then "Account Settings," then "Data Files," and finally "Open File Location."
• To rename a file, right-click on it and choose "Rename."
• Add .old to the end of the file name to convert it (for example, MyFile.ost.old).

Step 3: Make a new profile for Outlook

• Find "Control Panel" in the Windows Start menu.
• To launch the Mail Setup dialogue box, click on the "Mail" applet.
• To create a new Outlook profile, click the "Show Profiles" button and then the "Add" button.
• Give the new profile a name and then follow the steps to set up your email account in it.

Step 4: Open Outlook with the new profile

• When the new profile is ready, click "OK" to dismiss the Mail Setup window.
• Start Microsoft Outlook and choose the new profile you just created.
• Outlook will start creating a new OST file to take the place of the old one.

Step 5: Make sure your mailbox is in sync with the server

• Outlook will start syncing your mailbox with the Exchange Server when you create a fresh OST file.
• This procedure can take a while to finish, depending on how big your mailbox is.
• You may use Outlook as usual when the synchronisation procedure is done.

Use the tool for Outlook OST repair as the third method.

ScanPST can fix little problems with OST files, but it can't fix big problems with OST files. You may fix and convert the OST to PST using a third-party program like an Softaken OST to PST converter in these situations. Without utilising ScanPST, this is the easiest way to get back deleted mailbox items, password-protected OST files, and big OST files.

This is how to fix a broken OST file:

Step 1: Get the OST repair and conversion tool

1. To start, download and install the most recent version of the software on your computer.
2. To begin, launch the program on your computer.
3. Type in your email address and password, then click "Login." users who are new to the app may click "Start Your Free Trial" to get the trial version.
4. Choose "Outlook OST Recovery and Migration."
5. Pick "OST to PST" from the list.
6. You may either keep the default job name or click "New Job" to create a new job and give it a name.
7. After that, click "Next" to go on.

Step 2: Look through the broken OST file to fix it

Click "Browse for OST file."
Find the OST file on your computer and click "Next" to go on. Make sure the file has the right read and write access if it is on a network disc so that it may be opened and processed without any problems.
Click on "Browse."
Choose where you want to keep the PST files that you exported. Make sure you have enough free space on your hard drive to store things.

Step 3: Look at the mailbox and choose it

1. The offline OST file handles mailbox data, including files that have been corrupted or damaged. It carefully looks at the structure of the file to get emails and other parts of the mailbox.
2. When the restoration is done, the whole folder structure will be on the left side. To see what's inside, just open the mailbox and its folders. You can see emails, contacts, notes, tasks, calendars, and more directly in the app's preview window.
3. Choose the mailboxes and folders you need, then click "Next."

Step 4: Export OST files from Outlook

1. Check the mails and folders you choose for the export.
2. Set the "Action" to "Export," and then click the "Start Export" button.
3. The export process has begun, and you can see how it is doing in the progress bar. Check the log report to make sure the exported items are correct when the operation is done.

Step 5: Open Outlook and import the PST file.

Lastly, bring the PST file into Outlook. Once the import is done, you will be able to see all of the information that was extracted from the OST file in the PST file format.

1. Launch Outlook and click on "File."
2. Click on "Open & Export" in the "Info" box, then choose "Import/Export."
3. Choose "Import from another program or file" in the "Import and Export Wizard" and then click "Next."
4. Choose "Outlook Data File (.pst)" and then follow the instructions to begin bringing the file into Outlook.

Conclusion

We've looked at a few different techniques to fix damaged Outlook OST files. ScanPST.exe, which is incorporated into Outlook, may fix little problems, but it doesn't always work when there is a lot of damage or when there are orphaned OST files. When this happens, the OST to PST Converter is a better and more complete answer. Backing up your OST files on a regular basis is a good way to protect against losing data. The software lets you get data back from OST files that are broken, destroyed, or can't be accessed. It also lets you import directly into Office 365 and live Exchange setups. It works well with all versions of Windows and Outlook, keeping the original folder structure and formatting throughout the recovery and transfer procedure.