Managing personal Outlook.com account settings, security, and privacy
Hello,
Microsoft always recommends that account users have at least three verification methods active. So, even if one method is disabled, you can use another method to sign in.
Is Microsoft asking you to verify your identity using that recovery email address during sign-in?
If so, you will need to replace the Security information on your Microsoft account. That is, on the Verify Your Identity screen, select 'I don't have any of these' and follow the prompts to replace the Security Information.
Note - If you remove all of your previous security information and replace it with something new, your account will be put into a restricted state for 30 days.