How to Open/Convert OST to PST without Outlook

The term Outlook OST is fast gaining popularity and more and more people are becoming aware that it is just like a PST file that stores Microsoft Exchange data. An OST file stores Microsoft Exchange mailbox data in an offline mode on the local system. Hence, in situations where the Exchange Server is not accessible (for maintenance or server downtime situations), users can continue working with the OST file without interruptions. However, many times, OST files can become inaccessible or corrupted. If such a situation arises, the first way that you should try out to repair the file is by using Microsoft’s in-built ScanOST utility. However, this utility often fails to repair the problems within the OST leaving users in the lurch.

Hence, if the OST faces problems, the recommended way to go is to convert it to PST format. This article will be focusing on Outlook OST file to PST conversion without Outlook, why it is needed, and how to achieve it.

Why is Outlook OST file to PST conversion needed without Outlook?

Before delving into the depths of a matter, it is always good to analyze why we need the matter in the first place. Apart from situations where the ScanOST utility fails to work on a faulty OST, the following situations to demand the conversion of OST files into PST format:

1. MAPI Bindings
Typically, OST files are bound to specific MAPI profiles. Thus, an OST file can easily be opened on the system where the MS Exchange account was configured (with cached mode enabled). However, if you wish to access the data in the OST on another system, a simple copy-paste operation won’t do. You’ll have to convert the OST file to PST format and thereafter the PST file can be copied to the other system and accessed using Outlook.

2. OST Size Limit
With continuous usage over time, OST files tend to grow large in size. However, they’re not quite equipped to deal with huge volumes of data. They tend to become prone to corruption with their increasing size. Hence from time to time, archiving old OST data in PST format is a good way to play safe.

3. Orphan OST
If the Exchange Server account which is the parent of an OST file is deleted, is inaccessible, or is facing any technical issues, the OST file is considered to be orphaned. Attempts to access this file results in errors. Hence, the conversion of this file into PST format and subsequent accessing of data is the only solution left.

How to achieve the conversion of OST data to PST format:

Here are some simple ways to convert OST data to PST format:

1. Exporting OST emails to PST file

Although this method achieves your purpose, it is slightly less recommended since folder properties like permissions and views are not preserved after exporting the email data to PST. Only the content part gets exported. Hence, you should think of using this method only if you want to focus on converting the emails and that too quickly.

a. Go to File -> Options -> Advanced.
b. In the dialog box that opens up, click on Export and choose the Outlook data file (PST) as exporting medium.
c. Take care to check the other settings (Include Subfolders etc) as required.
d. Click on OK.

2. Archiving OST emails to PST file

Old data within the OST file should be archived from time to time to keep a check on the OST file size and also to better preserve important data. When it comes to archiving OST data, a target PST file is always the preferred choice. To achieve OST archiving in PST format, you can set an AutoArchive option by doing the following things:

a. Go to Tools -> Options -> Other -> AutoArchive
b. Select the option to “Apply to all folders
c. Go to File -> Archived. Run

This method too suffers from a limitation that is its inability to archive contacts.

3. Drag-&-Drop OST items to a new PST

This probably sounds the easiest. Create a new PST file in your Outlook profile and then drag the email folders from the OST file to this new PST file. However, you must take care of one thing while using this method – instead of dragging default folders (Inbox, Calendars, Contacts etc) as a whole, you’ll need to drag and drop individual content with target folder names changed (for example, Inbox (1), Calendar (1) etc).

This method sure is easy but frankly who has the time or patience for it!

4. Using third-party tools when Outlook is unavailable

Probably the simplest, most accurate, and straight-forward way to perform OST to PST conversion is to opt for a third-party tool. A recommended product for this purpose is Stellar Converter for OST. This professional converter easily exports objects in an OST file into PST format and stores the PST file at a user-specified location.

free download

Rating by MVP:


Final Words

After analyzing the different ways to perform Outlook Offline folder file conversion and their drawbacks, using a third-party tool seems to be the optimum choice. So go ahead with powerful software like Stellar Converter for OST and efficiently convert OST data to PST format without any hassles.

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