McAfee VirusScan for Mac conflicts with Outlook 2011, causing cache files to corrupt on server folders (like the Inbox and calendars). This leads to Exchange synchronization failures and errors.

Typical troubleshooting approaches only temporarily fix these problems, including: deleting the cache on folders, recreating the Exchange account, or rebuilding the Exchange database.

Until this is resolved by McAfee, the only permanent solution is to either uninstall McAfee VirusScan or configure it to exclude the Office 2011 identities folder (located in ~/Documents/Microsoft User Data).