Find Out Why Hotmail.ost Cannot Be Accessed

Maggie Scott ~ Modified: July 11th, 2022 ~ Data Recovery ~ 3 Minutes Reading

OST file is one of the greatest assets for the organizational level of users who cannot depend only on a restricted kind of environment. Microsoft Outlook when working with Exchange Server works in a client-server environment. Moreover, when the ability to work offline is required, a cache replica of the respective mailbox is then generated to render business continuity.

OST is one of the two data files created by Outlook. PST or the Personal Storage Table is the default data file that is created when the client is working individually. Meanwhile, OST is generated on enabling the cache mode during account configuration.

However, the OST file generation case is not only restricted to Exchange Server. While using an Exchange account, whatever is being exchanged through it, first is delivered to the server mailbox and a copy of it gets stored in the OST as soon as the mailbox and the cache copy sync.


Hotmail.ost Briefing

OST files are also generated when Outlook is setup up using Outlook Connector, which is meant for which is the successor of what was earlier known as Hotmail. The best part is Offline data files are the cache file or replica of the mail server data thus, do not require backup for business continuity, because what is in it, is there on the server and vice versa.

Common Problem With Hotmail OST

Where there is a connection involved, malfunctions or issues tend to take place. One of the cases has been explained below that involves a Windows 7 machine configured with Outlook 2007 using Outlook Connector.
At first, the connection works fine and everything is in proper synchronization whereas a slight change leads to the following error:

Consequences & Commonly Tried Hacks

Changing folder names or performing modifications with the account name could result in ceasing Outlook to work with Hotmail with the respective error displayed. Trying to delete and recreate the profile, changing the name or compatibility may fail but the two solutions that have the greatest chance of rendering successful results are:

  1. Renaming And Re-synchronizing: Renaming the existing OST file and then trying to synchronize it back mostly works in certain cases. This is like the recreation of the OST file, which in a way renews the sync between Hotmail and the file.
  2. Using Scanpst Utility: When Outlook keeps on creating an OST file every time, it will certainly have to recognize the OST file is generated automatically at first thus leading to the discussed issue. Repair the file with the Inbox Repair tool provided by Microsoft with Outlook (it works with both; PST and OST). Then, use the .bak file created for the OST by renaming the file’s extension to OST from BAK. Start Outlook and check if the sync works.

Observation & Conclusion: The discussed issue is either a result of technical error or repeated recreation of the OST file. Therefore, the proposed solutions are fit to resolve the issue and mend the condition to a better state. Otherwise, you can opt for the direct approach of offline OST to PST Conversion.