Currently, there is no rebuild option available in the new Outlook 2016 for Mac. So if you think the configuration of the profile is bad the you can create a new profile.
1. In Finder, browse to the Application folder. Press CTRL and then click Microsoft Outlook to see the contextual menu, and then click Show Package Contents.
2. In the Contents > SharedSupport folder, double-click Outlook Profile Manager.
3. In the Outlook Profile Manager window, click the Add button and give the profile a name.
Finally click the Options button and click Set as Default. This way when Outlook opens it will use this "new profile".