Hi Gary,
Using an Exchange account in Outlook, normally, you should have .ost file as your data file. Could you please let me know what you mean by "will not search pst's users might have configured"?
Also, how many clients are affected by this? Are you in Cached Exchange Mode or Online Mode?
"Playing with the indexing and user profiles appears to have no effect" - I'm not quite sure what exactly you've tried, generally, to troubleshoot instant search issues, you can follow below steps:
- Check if the pst-file or mailbox has been marked to be indexed: File-> Options-> section Search-> button Indexing Options-> button Modify-> expand Microsoft Outlook
- Disable and then re-enable the file for indexing
- Rebuild the index
- Check for pst-file corruptions with
scanpst.exe tool.
- Reinstall the Windows Search feature. If you are in Cached Exchange Mode, the instant search feature actually uses Windows Search feature. If it got damaged, you'll have search issues in Outlook.
Please try any steps that you haven't tried before in the list, and feel free to post back with any findings.
Regards,
Ethan Hua
TechNet Community Support