After rebuilding, the program continues to operate normally for a period ranging from a few hours to a day at which point the program will close itself and then prompt the user to rebuild the identity once again. This account is Office 365 and is added as Exchange and from what I understand shouldn't have the identity rebuilt. So far we have tried:

-Rebuilding the identity

-Clearing the email account and creating a fresh profile then adding the email account once more.

-Repairing Disk Permissions

-Creating a new Identity

-Completely uninstalling Office 2011 and removing preference files, library files, daemons, etc and then reinstalling the program from scratch. It is currently the latest version.

Currently running OSX Yosemite with 32GB RAM and plenty of HD space. When the program stops functioning it does not display an error message, it simply prompts the user to rebuild the identity.

Does anyone else have any further suggestions for troubleshooting?