Email associated with Xbox account

You signed in with a different email than what is with the account that is associated with your xbox 360 profile you can find the email associated with that profile by signing in on the account on the 360 going to settings and account and then billing info
and it will show you the email address that is associated with that gamer tag

Hello,

It means you already have a Xbox Account associated to your Email you put in for your new account. Try using another email. Or change the email address of the account associated with the Email you are trying to use.

How do I go about doing that?

First, add your new Microsoft email address by signing in to https://account.microsoft.com/profile.

Once you have added the email address, set it as the new primary email address. After that don’t make any changes with the previous Microsoft email address, it will be set as secondary email on your account.

The detailed steps can be found on the link as well.

Hi GoldenDr4gon999, I hope you're doing great out there. I am an Independent advisor and I am here to help you in regard to your concern.

Yes, that would be possible. You just need to change the primary alias for your Microsoft account and then you will not delete or remove your current primary alias means that your dad's account will still be linked to your account but as a secondary email.

Because according to Microsoft: "Warning When removing an email alias that’s connected to a Microsoft domain (such as @Outlook.com, @Live.com, or @Hotmail.com), that email is completely deleted from our systems and can’t be used to send or receive emails. It won’t be available for use again as an alias on another account. Microsoft doesn’t recycle email addresses, so it can’t be reclaimed at a future time."

For your reference, you can check this link: https://support.xbox.com/en-US/help/account-pro...