Hi All,

I could not find pst file in outlook 2010 . But I am able to find the ost file. Exchange server is 2013 and client os is windows 7.

How can i find the pst file. 

Whenever configuring outlook,  will it by default create pst and ost file? Or do we need to create pst files manually.

What is the main difference between pst and ost?

If you're connecting Outlook to an Exchange account there won't be a .pst file.

The .pst file is basically the local storage of a mailbox when you use POP3 for your email (eg the mail lives solely on the local machine), or the file you'd use if you exported the mail to a local file.

The .ost is the local copy of a mailbox which actually resides on an Exchange server, and is used when you've enabled cached mode in Outlook.

To find the files and their locations for any mailboxes you have configured in Outlook, go to File, Account Settings, Account Settings..., and then select the Data Files tab. You'll see one file location per individual mailbox configured in Outlook and you'll see where they are Exchange mailboxes the relevant file is an .ost file, while for POP3 it's a .pst.

Great and accurate information from Keith and a few additional details;

1. OST files can only be used on the machine and profile they were created under, i.e. unlike PST files you cannot transport and open OST files on alternate machines.  The only way around that is if you purchase a 3rd party tool that can open OST files.

2. When you are connected to the users mailbox via the Exchange Server OR via the OST file you can export all items to PST if desired, however it would just be the equivalent to a backup of the mailbox.  Not a ver efficient one mind you, i.e. better to backup at the server level