New mac user, have an issue with Microsoft Outlook 2011. The account is using IMAP and SMTP to access a web mail server, not Exchange. I use Outlook primarily for the integrated calendar and how easily it works with most meeting requests. Anyway everything was fine until about 2 weeks ago when my outlook started re-downloading all my mail on a sync. It happens about 3 times a day, I think whenever I navigate from the calendar section back to the mail section and it checks for mail. To be clear, it is re-downloading mail not duplicating.

Mac OS 10.9.4
Outlook 2011 version is 14.4.3

I have tried the following suggestions I have found so far with no luck:
1.) Set Outlook application to "Prevent App Nap"
2.) Turned off storing a local copy of Sent Mail
3.) Rebuilt Outlook Database

Most online suggestions are dealing with POP accounts not IMAP, and outside of these suggestions I am running into a wall. I am posting here in hopes that you guyz can save my bacon else, I am going to have to find a new app for email.