Mac OS X El Capitan arrived with many errors and compatibility issues. Microsoft is aware there are issues with the Outlook, Exchange and the release of El Capitan. There is also an update for Office 2011 that ca you download using the link below.
Support page: https://support.microsoft.com/en-us/kb/3098229
Apply the update and then try again and watch the behavior. There is no other solution except the one with the update.