The OWA ZynBit web add-in supports Outlook for Mac 2016 with Office 365, Outlook Web Access (aka Outlook.com) and Outlook for Windows (Outlook 2013 & 2016). To install the plugin you must have appropriate rights on your Exchange Server.
In outlook Desktop, open the file menu and select Manage Add-ins at the bottom.
Click the + sign to add a new icon and Add from Office Store.
Search for ZynBit and when the icon appears, click it to install.
Return to email and open an item. You will see the ZynBit Icon and clicking will display the side panel on the right side of your screen. The first time you launch, you will be asked to connect using the same login information you use for ZynBit.com. After this, the connection information is retained.
Once connected, you can bring up the sidebar whenever desired by clicking the ZynBit icon on any email.