Old gamertag not linked to a Microsoft account

I know the email address I used but it doesn't work for logging in or recovery methods. I actually tried all of my email addresses. When I created the account, it didn't require a Microsoft account.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://support.xbox.com/it-it&ved=2ahUKEwjEi73e4LDkAhUDC-wKHcGWB-cQFjAAegQIBxAD&usg=AOvVaw0DtUiJlm8AYVL9WAjJ3kYN

Hi StevoTVR,

If you created a gamertag, then it created a Microsoft Account for you at that time. You need to have a Microsoft Account to use Xbox Live services, including a gamertag and whatever email was chosen or made at that time is the one that is linked to the
gamertag/Microsoft Account.

Recently there was a policy change to the
Microsoft Services Agreement regarding Account use/activity where a Microsoft Account will close after 2 years without logging in, although there are some exceptions that you can read from the actual policy change: https://support.microsoft.com/help/4511051/microsoft-account-activity-policy

Before it used to be 5 years so either way if you did not log in to the account during that time, then the account is likely closed and the gamertag was released.

Yes, that's my old account. What would keep an account from being released?

It's been a long time, so it's likely
not possible as many of the old accounts were retired/released. Take a look at the requirements, and see if your account might have met any of them to prevent it from being released for public use again. Though I am seeing that account on Xbox Live with
achievements in GTA 4 and Dirt 2 for GFWL. Does that look like your account?