Is it possible to find the email address linked to my old gamertag?

Have you tried the steps
here

I signed into the gamertag/xbox account earlier today, realised it was linked to an old hotmail address, and was trying to change the associated MS account's email from that hotmail address to my gmail address.

Hi, thanks for your reply.

When I click that link it asks me for an email address. Is this for my son's account or mine? Something I noticed on our xbox is that my two younger sons have gamertags but their email addresses are not connected to these, and I can't find a way to link the two without it trying to create a new gamertag for their emails.

Thank you for your swift response!

However, to link my old email address to my hotmail account is not possible as i can only link other hotmail email addresses to my hotmail account.

I tried to recover my old email address and was informed by the email address provider that it was not only deactivated but also terminated and not recoverable as i havent used it in 10+ years.

Is there any other way to help change my old xbox live email address? Perhaps microsoft could change it manually? Given that i can verify that it is my account via Identification card, phone number or facebook as i use the same email address there as i do on my xboxlive account.

It is not possible to have 2 gamertags associated to the same account. It is also not possible to transfer gamertags from one account to another. So the only possible explanation is that you have 2 different accounts with different email addresses used
to log in. To try to find the email address used to log in to the other account please use the Forgot email address for
Microsoft account solution.