New Microsoft login - verification selects old email address

When logging into a new microsoft account on a new laptop, the verification email address that comes up is an old address that has been out of use for 9 months, it does not exist.

I have never entered this old address on the new account. I've checked the 3 other microsoft accounts I have and none reference this old address.

What is going on? Is it being stored somewhere? How can I stop it appearing?

Thank you.

PS: your tag options don't include operating systems and logins!