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 of the screen. A browser window will open with your email add-in options shown. Click the + sign to add the plugin and Add from Office Store. Enter ZynBit in the search bar and when the Zynbit icon appears, click it to install. Click Add in the window that follows, and then Install on the third screen. If you see ZynBit already listed in your plugin list, just check the box and the plugin will load.
Return to email and open an item. You will see the ZynBit icon in your email toolbar, and clicking will display the Zynbit 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 to set up your ZynBit account. 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. Alternatively, there is a pin on the top right side that will cause the ZynBit pane to remain visible as you open and close emails.