Outlook 2007- emails “disappearing”

I received a complaint today that emails sent over the weekend weren’t forwarding properly to one of our employees. We run Outlook 2007 and do not currently have our Exchange server running, so emails are saved to individual psts. When I checked the emails were not there as they had said, however they would show up as if they were properly sorted to the correct folder when I ran a search. I tried recreating the rule and applying it to the email, which it claims to do successfully, but the email is still invisible unless searched for.

I have a feeling that this is happening to other employees and they just haven’t noticed.

Finally, I should mention that our net admin has recently pushed out Symantec Endpoint Protection 11.0 .