Outlook error "Cannot open your default email folders" when setting up exchange email (work in OWA and iphone)

Outlook error Setting up Exchange

I can set up send/rec a test email account via iphone and see the account in OWA

But when I setup via Outlook 2007 ..


Cannot open your default email folders. The file c:\ ................ outlook2.ost cannot be accessed.
You must connect to MS Exchange at least once before you can use your offline folder ...
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JohnBusiness Consultant (Owner)Commented:
Cannot open your default email folders. The file c:\ ................ outlook2.ost

Message is accurate and correct.

You must use Exchange to see your email in Outlook.


You can use a third party tool (Stellar Tools) to convert the OST file to PST and then open it.

You cannot open an OST file.
JohnBusiness Consultant (Owner)Commented:
The OST file has to have a connection to Exchange to work.  So the Exchange account needs to be working.
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what version of Exchange you are using??
Marshal HubsEmail ConsultantCommented:
As @John suggested, You can use Stellar to convert the OST file to PST and then open PST in MS Outlook. You can download the software from here: https://www.stellarinfo.com/convert-ost-to-pst.php
SysToolsData Expert - Recovery,Backup,MigrationCommented:
There are many workaround approaches to resolve the issue "Cannot open your default email folders. The file c:\ ................ outlook2.ost cannot be accessed." causing unavailability of the Outlook OST file. All of these methods are discussed in this section.

#Manual Method 1: Exit All Processes Related to Outlook

1. Exit Outlook application and open task manager
2. Navigate to the Processes tab and search for the names like Communicator, Lynk, and UCMAPI
3. Choose each process at a time and select the option “End task”

#Manual Solution 2: Deactivate Exchange Cached Mode

1. Move to the Control Panel >> Mail >> Email Accounts >> Email
2. Then, select the suitable email address and select the option of “Change” from the navigation bar
3. Select the option Use Cached Exchange Mode to fix the error OST file cannot be opened Outlook 2013
4. At last, press on Next button and then, Finish

#Manual Solution 3: Disable the Add-ins

1. Open Outlook application and switch to File >> options >> Add-ins
2. An Outlook Options window will appear on the screen. Choose COM Add-in option under the heading Manage and click on Go

3. At the next step, insert or remove the add-ins.

#Manual Solution 4: Launch Outlook in Safe Mode

1. Search Outlook.exe icon and press the Ctrl key and double-click on it
2. In the next step, a dialogue box will ask for confirmation. Click “Yes”

#Manual Solution 5: Using Scanpst.exe to Fix OST File Cannot be Opened

Scanpst.exe is an inbuilt utility to repair the Outlook data files and make them available to the users. It is an effective solution to repair the OST files with minor fault. Also, it does not scan the sub-folders and scans the main folders. To use the scanpst.exe option, users have to follow these set of instructions:

1. Go to the folder where Outlook.exe file is stored. There, scanpst.exe file will also be present, double-click on it

2. Browse the file that you want to open and click on Start to repair the .ost file and get the error fixed

Professional Solution to Remove Error- OST is in Use and Cannot be Accessed

To eliminate the errors in OST file, users can switch their OST file to the PST file format. This can be done by using the SysTools OST to PST Converter. According to the experts, it is the best possible solution to move from .ost file to  .pst file format. The user interface of the tool is so simple that even a novice user can use it without any issue.

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SysToolsData Expert - Recovery,Backup,MigrationCommented:
All suggestion are useful, please close it.
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