How to fix an Outlook .ost file
When issues occur and the suspected cause is an error in an underlying OST file, many people try correcting the issue using ScanPST.
The reality is that the best way to resolve issues with an OST file is to allow Outlook to recreate the file. With Outlook closed, just need to locate the ost file in question and rename it. Outlook will automatically recreate the file when it can’t find the original and re-sync with the server. The reason for renaming the original .ost file instead of just deleting it is because, should the need arise because of some unexpected problem, the renamed file can be renamed back to the original file name which Outlook will use when Outlook is opened again.
One very important caveat to remember when doing the above is for IMAP based .ost files. If contact/calendar data exists within the IMAP folder tree (those would be labeled as “This Computer Only”) then that data must first be exported to a PST file or the data will be lost. Contact/Calendar data does not sync with the server for IMAP accounts. You will then need to import these folders back into Outlook or preferably take steps where you will not be prone to losing this information in the future should the email account and/or ost file ever get deleted.
Related articles for Imap contact/calendar data
How to Protect Outlook ‘2013/’2016 Imap Contact/Calendar Data
How to sync POP3-IMap contact/calendar data
Category: Outlook - How To, Troubleshooting
