Windows Mail: Your Outlook account settings are out of date

That's nice, Windows, especially since I don't have an Outlook account. But this annoying message keeps popping up anyway. I have only set up Windows mail with a Gmail account, but it keeps blathering about a non-existent Outlook account. Poking around in the app, I did find an Outlook entry in my calendar, but I have no idea how it got there. If I click on Settings>Manage Accounts, there is no Outlook account there, only the Gmail account. Anyone know how to resolve this nonsense?

Never mind, found the "Outlook account" in general Windows settings instead of the Calendar settings. Deleted it; problem solved. Not sure why I couldn't manage the account from the mail/calendar app where the error was appearing.