Using classic Outlook for Windows in business environments
I am having the same problem adding my Outlook. It added fine to the old Windows email but whenever I tried to add it to the new it just failed. This didn't bother me so much as I didn't like the new version anyway so I continued to use the old version where it was available. But now I've been forced on to the new version which has both functionality, and doesn't now have all my email addresses.
I'm not sure how to make the Outlook my primary email as suggested here previously. I don't have a ribbon that others have mentioned. I use my email online.