Case 1: Open OST File on Another Computer Manually
In this case, you don’t need the OST file in order to get your email data.
On the second computer, simply login with your credentials in the Outlook client (and configure it with IMAP protocol), and it will fetch your email and other data from the exchange server. After this, a new OST file will be generated and saved in the designated folder of your new machine.
Essentially, this was an automatic process where after you logged in, your OST file was copied and opened in the different computer. You can now view all your emails, send/receive new emails and so on.
One thing to consider – Before configuring Outlook on your new device, it’s a good idea to connect the first computer to the Internet so that whatever changes were made to your local OST file can be synchronized with your email data currently hosted on the server.
It is the quickest way to open OST file on another computer without any limitation.
Case 2: Open OST on Another Computer After Exporting in PST Format
In this case, using the OST directly in Outlook can be tricky. The solution is to convert the OST to PST format and then use the converted PST on any computer installed Outlook.
Let’s go step-by-step to understand why we can’t open OST file in another computer’s Outlook, and possible solutions you can work with.
What is an OST file?
Offline Storage Table (OST) is one of the two data storage files in Outlook (the other one being PST, aka Personal Storage Table). OST is a slave copy of the Outlook data (emails, calendars, contacts, task, etc.) which is present on your Email (by default, Exchange) Server WHEN you have configured your account to use IMAP protocol. This copy is stored at C:\Users\%username%\Documents\Outlook Files, in Outlook 2010/2013.
The advantages of generating this OST file –
You can view your email data even when you’re not connected to the Internet or when the email server is down.
Not just viewing, you can also edit your data, for example, you can delete emails, create emails, save emails as draft, add items to your calendar, etc.
The limitation of an OST file is that OST files cannot be opened directly in Outlook unless you have the same account that created it configured in Outlook client. This is because of an authentication process that happens when you use the OST for the first time. The server authenticates with your local device, and if that’s successful, it allows you to view the OST.
Such stand-alone OST files are termed as “Orphaned OSTs”.