In the last week or so I've noticed that the advanced find feature in Outlook no longer reliably works. For example, I put in sent by me and today and nothing comes up, even though there are lots of e-mails sent. Or a search only returns the last 3 months of results with nothing before that. I've reindexed Microsoft User Data in the "Privacy" tab of Spotlight in System Preferences and nothing has changed. (To be honest, I added the folder as recommended, closed System Preferences, then opened it again and removed it but nothing really seems to have happened since I don't know how to tell if the reindexing actually worked).

Any ideas how to get the very valuable search function back up and running robustly again would be greatly appreciated.

Thank you!

Outlook for Mac 2011 v14.4.7

Yosemite 10.10.1