Solved: Cannot Open Your Default Email Folders in Outlook

When accessing your Outlook email, does it show an error – Cannot open your default email folders? You can find out in this article to learn the quickest way to fix it.


By Yuka Updated on February 24, 2023

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What’s Causing ‘Cannot Open Your Default Email Folders’?

Cannot Open Your Default Email Folders

In our daily work, nearly 100,000 companies rely on Outlook for business communications. Its client is easy to use and comes with many basic functions that can meet the needs of most individual or business users.

Normally, you have no problem accessing Outlook emails. But sometimes a "Cannot open your default email folders" error message pops up, preventing you from seeing your emails. If you have encountered this problem, don't worry, this article will provide you with several effective methods to solve it. But before solving the problem, let's take a look at what may cause this error message to appear.

  • Your .OST file, also known as your offline Outlook data file, is corrupted and needs to be repaired or replaced.
  • You are running Outlook in compatibility mode.

Now that you know the possible causes, let's see how you can fix the "Outlook cannot open your default email folders" problem.

How Do I Fix Cannot Open Default Email Folders?

Follow these detailed troubleshooting steps below to quickly fix the error and regain access to your default email folder.

#1. Delete a Corrupted .OST File

OST files are offline storage tables that hold a copy of the original mailbox on the Exchange server. This copy is synchronized at specific time intervals. Thus, it enables the account owner to access the mailboxes all the time, even if there is no server connection.

To rebuild the .OST file, first delete the old configuration file that you are not using. Follow the path mentioned below to delete it.

  1. Click the Window + R to open the Run box.
  2. Copy and Paste %LOCALAPPDATA%\Microsoft\Outlook in the Run box and then, click the OK button.

Outlook Run Command

  1. This will take you to the OST data file location. Now, locate and right-click on the corrupt OST file which you want to delete. Click the Delete option.

Delete .OST File

🥯 Note: Now, by opening your Microsoft Outlook application, Exchange Server will automatically recreate the .OST file if there is no synchronization problem.

#2. Create a New .OST File

If the error that “Cannot open your default email folders” in Outlook 2010 is still not resolved after going through the above steps, then create a new configuration file.

  1. Open Microsoft Outlook and click the File tab.
  2. Select the Info option and click Account Settings.

Account Settings

  1. In the Account Settings window, select the Email tab and select Microsoft Exchange.

Microsoft Exchange

  1. Now, the system will display the Change Email Account, click the More Settings button.
  2. In the Microsoft Exchange window, select Advanced and click Offline Folder File Settings.

Offline Folder File Settings

  1. In the File box, type the path you want to use as the .OST file, and click OK. The default name is Outlook.ost. If this file already exists, you will be prompted for a new name. If you see this message, click OK.
  2. Click OK, Next, and then click Finish.

🥯 Note: Outlook must be connected to the Exchange server for the initial creation and synchronization of the offline folder files.

#3. Turn Off Compatibility Mode

If you are still seeing the error message "Cannot open your default email folders", you are probably running Outlook through compatibility mode. All you need to do now is to turn off "compatibility mode".

  1. Navigate to C:\Program Files (x86)\Microsoft Office\Office XX\Outlook.exe.
  2. Right-click on Outlook.exe and navigate to Properties > Compatibility tab.
  3. Uncheck the Run this program in compatibility mode box, click Apply and OK

Compatibility Mode

#4. Run Your Outlook in the Safe Mode

Faulty plug-ins can cause errors in the smooth functioning of Outlook. When you run Outlook in safe mode, it disables all installed plug-ins and allows you to access Outlook's default email folder.

  1. Press the Windows + R keyboard shortcut to open the Run dialog box and type outlook.exe /safe.

Outlook in Safe Mode

  1. Select Options - Default Outlook and click OK. Your Outlook will start in safe mode. Then see if it comes up with the message - Outlook cannot open the default email folder.

Foolproof Way to Keep Your Outlook Email Safe

Email plays a very important role in our daily life and work. If they are accidentally deleted and damaged, you will lose them completely. Or if you encounter the "Cannot open your default email folders" error in Outlook 2010, it can cause inconvenience to your work or life. To ensure that you always have timely and secure access to them, it is recommended that you backup Outlook emails regularly. Here I recommend you the best Outlook backup software - AOMEI Backupper Professional.

🍿 You can use it to backup Outlook data including emails, attachments, calendars, contacts, etc.
🍿 You can use it to set scheduled backup feature to run Outlook email backup automatically. You can choose the time frequency like daily, weekly, monthly etc.
🍿 You can also select "Incremental backup" or "Differential backup" in Backup Scheme to back up only changed files, which will save you a lot of time and disk space.
🍿 You can use it to backup Outlook emails to external hard drive, USB drive, network or NAS device, cloud drive, etc.

Download Free TrialWin11/10/8.1/8/7/XP
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  1. Open Outlook and make sure you are logged in with the account that contains the emails you want to back up.
  2. Launch AOMEI Backupper Professional and click Backup and Outlook Backup.

Outlook Backup

  1. Click Add Outlook Data and then select the account whose emails you want to backup. Then click OK.

Add Outlook Data

  1. Click the second box to select a destination to store your Outlook emails.

Select Destination

  1. You can click Schedule Backup to set up automatic backup of Outlook emails and then click Start Backup.

Schedule Backup


This article explains the possible reasons for "Cannot open your default email folder" in Outlook and 4 effective ways to solve this problem. If you are struggling with this problem, follow the tips in the article to check the cause and fix it completely. Also, if you don't want to lose any important data in Outlook, it is recommended that you backup Outlook emails frequently.

The backup software provided in the article has many other useful features, such as cloning. If you want to upgrade your computer's hard drive, you can use it to migrate data and systems. This avoids the hassle of reinstalling the system and setting up a new computer. Feel free to download it and try it out.

Yuka · Editor
Yuka, our dedicated editor at AOMEI Technology, is committed to bringing you valuable insights and guidance in data protection. Her mission is to empower everyone with her knowledge in computer backup and recovery, disk cloning, file synchronization, and more. Yuka's goal is to do her best to make complex tech tasks simple and ensure that your digital world remains safe and secure.