Hi @Tom Luley ,
Before going further, I'd like to confirm the following things with you so that we may understand better about the situation:
- Do you have idea about when the searching issue started to occur and when it began grow rapidly? Was any change made in the environment before the issue started?
- For the two examples you mentioned, could you please provide more details like which keyword did they use when attempting to search, and what was returned: no results, wrong results or incomplete results?
How about changing the search scope to “Current mailbox” or adjusting the keywords to see if there would be any difference?
- Searching for most things works, but more and more calls from users are coming into the helpdesk with various searching issues and I am not sure where to start since they are so intermittent. Agree with you that it could be quite hard to troubleshoot given the current situation that the reported searching issues are various and intermittent. So if possible, can you try to go through some more examples and see if there could be any findings? You can also share some more typical examples after removing any personal information involved for further investigation.
For situation similar to the first example that the message can be found in OWA, I’d like to suggest testing in Outlook client side by switching between Exchange cached mode and Online mode and see if there would be any difference.
Besides, please have a check on the Exchange server to see if there are any relevant logs in the Event Viewer.
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