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.

Delete the original offline Outlook data file (.OST) from the default location. Open Outlook. This will recreate a new OST Outlook data file. This fixes most issues you may encounter while using ...

Repair corrupted Outlook .pst and .ost files with Inbox Repair Tool (ScanPST.exe), OST Integrity Check tool (Scanost.exe), OLFix and Fix It.