Can't stop iCloud prompt at startup and throughout the day
Ever since I downloaded OS10, I can't stop the iCloud prompt. It refers to an addy I haven't used in nearly 4 years and was with another ISP. I've never used it on this computer which is 3 years old. I don't remember any passwords associated with that addy and can't access iTunes with it, which Sierra insists on. My current iTunes login doesn't work for this iCloud problem, it only wants the outdated info. Oddly, I didn't have a Mac when I used that addy and had never even used any cloud, much less iCloud.
This is hardly earth-shattering, but it is annoying. Anyone have ideas on how to get rid of this prompt that happens about every hour? All I can do is click "Later", but "later" is always an hour. Thankyouthankyouthankyou.
Mac mini (Late 2014), iOS 10.1.1