We have Exchange 2010 SP3 RU4 and Outlook 2010. We have alot of users who when searching for mail items in the outlook client or OWA, it fails to find all the results, so if a user searches for an email from sender Tommy, it will find a lot of Tommy's emails but some will not be found. I noticed that the ones that are not being found are emails with pdf attachments specifically. It finds Tommy if there are no attachments or the attachment is anything other than a pdf. I have moved the user's mailbox to a different mailbox DB, I have re-profiled outlook (but this happens in OWA also), I have also stopped and restarted the Microsoft Exchange Search Indexer on the Mailbox Servers, and I have also made sure indexing was setup on the outlook clients. Any ideas on what may be causing this. Like I mentioned it happens in outlook client and OWA.