Recently had an issue where a user who was a carried over from Exchange Server 2003 way back when had multiple corrupt items. When he was originally migrated to Exchange Server 2010 there were a number of items which so how got corrupt. This inhibited his search abilities. With the New-MailboxRepairRequest command in Exchange 2016 I was able to resolve this issue.
I ran the repair against all options:
Once complete we recreated the user’s .OST file since he works in cached mode.
You can find more info on this at Technet: