To set up Microsoft Outlook for Mac 2016 to check your Office 365 email account, follow these steps:

1. Open Outlook for Mac 2016.
2. Choose Always Allow on the dialog box that appears stating Microsoft Outlook wants to use your confidential information stored in your keychain.

Outlook for Mac 2016 dialog box requesting keychain access. Instructions as above.

3. Press the light blue arrow button on the right hand side of the Welcome to Outlook screen.
4. Press the blue Start Using Outlook button at the bottom of the You're All Set screen.

Your email account is now ready to use.