Read Ost File Without Outlook

Microsoft Outlook 2010 doesn’t support manually opening or importing items from an offline Outlook Data File (.ost). Note: By default, when you add an account that uses an offline Outlook Data File (.ost), the file is automatically created and data from the server is downloaded.

Also, if you specify a new folder location for the offline Outlook Data File (.ost), a new file is automatically created.

Although not required, you can manually move the existing file to the new folder to avoid the download time that is required to re-create the file.

  • Outlook Data Files (.ost) are used when you have an Exchange account and want to work offline or use or use the default Cached Exchange Mode.
  • This type of data file is also used for accounts that you set up with the Outlook Connector for (formerly Hotmail).
  • Outlook Data Files (.ost) are always copies of items that are saved on a mail server and don’t need to be backed up like Outlook Data Files (.pst).

Offline Outlook Data Files (.ost) are copies of your Exchange information. It is not necessary to back up this file.

You can create a new copy at any time. In Control Panel, click or double-click Mail. Where is Mail in Control Panel? Mail appears in different Control Panel locations depending upon the version of the Microsoft Windows operating system, Control Panel view selected, and whether a 32- or 64-bit operating system or version of Outlook 2010 is installed.

The easiest way to locate Mail is to open Control Panel in Windows, and then in the Search box at the top of window, type Mail.

  • In Control Panel for Windows XP, type Mail in the Address box.
  • Note: The Mail icon appears after Outlook starts for the first time.
  • The title bar of the Mail Setup dialog box contains the name of the current profile.
  • To select a different existing profile, click Show Profiles, select the profile name, and then click Properties.
  • On the E-mail tab, select the Exchange account, and then click Change.

Clear the Use Cached Exchange Mode check box.


  • Click More Settings. On the Advanced tab, click Offline Folder File Settings.
  • Click Disable Offline Use, and then in the dialog box that appears, click Yes.

Why One Has to Open OST File Without Outlook?

Note: If you cannot click Disable Offline Use, this indicates the Use Cached Exchange Mode check box was not cleared in step 4. This check box must be cleared.

  • Again, click Offline Folder File Settings.
  • In the dialog box that appears, click Yes.
  • Under Cached Exchange Mode Settings, select the Use Cached Exchange Mode check box.
  • Click OK, click Next, and then click Finish.
  • In the Account Settings and Mail Setup dialog boxes, click Close.
  • You can convert OST file to PST file . There are several methods to convert OST file to PST file.
  • First, Microsoft does not provide an official tool to do the conversion.
  • However, if you can access the contents of the OST file in your Outlook, then you can perform the conversion manually, as follows:.
  • Make sure you can access all the contents in the OST file to be converted.

Create a new PST file. Go to the OST file, select and copy all the contents to be converted with your mouse.

  • Go back to the new PST file, then paste all the contents into the PST file.

That will do the ost 2 pst conversion. You can also perform the conversion by exporting the contents of OST file to PST file by following the instructions at: .

Second, if you can access the Exchange server containing the account data for the OST file, then you can use Export-Mailbox command to export the data into a PST file, similar to convert your OST file into a PST file.

Below is the article about doing that: . Third, you can try a free OST to PST converter via Outlook VBA . Below is the article about doing that:. Hope this will help.

3 found this helpfulthumb_upthumb_down. Summary: An OST viewer software helps view and read Outlook OST files that are in inaccessible or orphaned state and can’t be accessed via Outlook.

5. Aryson OST Viewer

In this post, we’ve discussed top 5 free OST viewer Software that allows you to view, read, and convert mailbox items in OST file to Outlook PST format.

OST is encrypted by default with MAPIEntryID GUID. Thus, OST is bound to the MAPI profile and requires authentication to access the mailbox data stored in it.

But if the OST file gets damaged due to Outlook crash or other system errors, it may become inaccessible.

Further, if the MAPI profile is deleted or removed from the mail server, the Outlook OST enters into an orphaned state and can’t be accessed from any Outlook profile. However, you can view any OST file, including orphaned and inaccessible OST file, by using an OST viewer tool.

The software allows you to view and extract mailbox items stored in Outlook OST data files without authentication.

The tool also helps you get back access to mailbox items stored in inaccessible, damaged, or orphaned OST files. Below we have discussed 5 free OST viewer tools that you can download on your Windows PC to scan and read OST file without any size limit.

Stellar Viewer for OST is an easy-to-use free OST viewer software that comes from Stellar®, one of the most reliable and trusted data care brands in the world. The software enables you to search, scan, and preview mailbox items stored in an OST file.

It also provides search options and filters, such as the ‘subject line’, ‘From’, ‘To’, ‘CC’, ‘BCC’, to locate and view specific emails or mail items.

Further, it also allows users to save or export the mailbox items to EML, RTF, MSG, PDF, or HTML formats.

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