To do this in Outlook for Mac, select Preferences, select General, and then select the Hide On My Computer folders check box. You can hide the On My Computer folders to prevent this behavior from occurring again. Move all your contact data to the Contacts folder in your Exchange account.Move all your calendar data to the Calendar folder in your Exchange account.To work around this behavior, take the following actions: When you add appointments or contacts to the On My Computer folders in Outlook for Mac, they are local to the Mac and do not synchronize to Microsoft Exchange Server. When you add appointments to your Calendar folder and add contacts to your Contacts folder in Outlook 2016 for Mac or Outlook for Mac 2011, the added appointments and contacts do not synchronize to Outlook Web App or to your mobile devices and other mail clients. Applies to: Outlook 2016 for Mac, Outlook for Mac 2011, Outlook for Mac for Office 365.
Added appointments and contacts in Outlook for Mac do not synchronize to Outlook Web App
