What data file types does Outlook support? While working with Outlook, you will encounter two data file types: OST and PST. OST (Offline Storage Table) file types allow you to work offline.

Alternately, you can locate the Outlook OST file using Windows Explorer. Open Windows Explorer, click the "C" drive icon, and double-click the "Users" folder to open it.

If you get Your Outlook data file cannot be configured error when opening Microsoft Outlook and your email account, see this post for the fixes.

Use the Inbox Repair tool or disable add-ons to recover your .PST and .OST files in Microsoft Outlook Classic and New ...