Using New Outlook on Windows for personal email, calendar, and contact management
Hello Linda,
They can sometimes end up in hidden places like the Sync Issues or Lost and Found folders if you’re using Exchange or IMAP. If the move failed completely, they might have been deleted, so check Recover Deleted Items under the Folder tab in Outlook. Another good step is to search your entire mailbox using keywords from those emails—they might still be in another folder.
If you were using a local PST file and it’s full or corrupted, the emails could be stuck in the data file, and you can try repairing it with ScanPST.exe (Inbox Repair Tool).
This might help