Why is FileLocator Pro not showing all emails in my OST file?

Question

I have created an index using Index Manager that indexes Outlook files - PST and OST files.

In general, searching the index works fine. However, I've noticed that there are sometimes results missing when I search I index. When I search using the same keyword in Outlook, it does show the email (The same OST file in the index is attached to my Outlook client as well). It's a simple one-word search, so I know that the search term is not causing the issue. I am able to reproduce every time.

Answer 1

The issue is resolved. The root cause was that my local Outlook OST file did not have a copy of all the emails on the server. There is a setting in Outlook that controls how many emails on the Exchange server are actually downloaded to the OST file. In my case, the setting was configured for the last 3 months, so only the emails from the last 3 months were in the OST file.

When searching in Outlook, it was searching for emails on the server (and not just my local OST file), and that explains why FLP could not find the email, because the email was never present in the OST file in the first place, so there was no way FLP could index it. I have changed the Outlook setting to download ALL emails from the server to the local OST file, and now FLP is able to find all emails. The specific option I used to download all emails from the server to the local OST file is called 'Mail to keep offline', and is documented by Microsoft here:
https://support.office.com/en-us/article/Change-how-much-mail-to-keep-offline-f3a1251c-6dd5-4208-aef9-7c8c9522d633

To summarize - This was an issue with my local OST file, and not with File Locator Pro :)