When using Microsoft Outlook to access a corrupt or orphaned offline folder (OST) file, or synchronizing it with the Exchange server, you may encounter a variety of error messages. To help you understand these errors better, we will provide a list of the most common ones, organized by frequency. For each error, we will outline its symptom, clarify its underlying cause, and offer a solution. In the following list, ‘xxxx.ost’ will represent the problematic Exchange OST file name.
- “Cannot open your default email folders. The file xxxx.ost is not an offline folder file.”
- “Unable to expand the folder. The set of folders could not be opened. Errors could have been detected in the file xxxx.ost. Quit all mail-enabled applications, and then use the Inbox Repair Tool.”
- Encounter numerous conflict items.
- Cannot open certain Outlook items when offline.
- Various errors when synchronizing Exchange Server mailbox with your OST file.
Moreover, when using offline folder (OST) file with Microsoft Exchange server, you may also encounter the following problems frequently, which can be solved by DataNumen Exchange Recovery easily.