It looks like this email is used with more than one account from Microsoft

Hello, first it's a pleasure to be able to help you today.

My name is welcome to the community.

Hello Delinquent8438, I did a quick search and found a case in our community that might help you.

https://answers.microsoft.com/en-us/windows/for...

https://gcits.com/knowledge-base/remove-work-or...

https://www.thewindowsclub.com/how-to-remove-wo...

Note: This is a non-Microsoft website. The page appears to be providing accurate, safe information. Watch out for ads on the site that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the site before you decide to download and install it.

the only way for there to be two gamertags on one email is a system glitch, there is more than likely a different email being used as the Microsoft account for the old gamertag

Yes you can change the email account from you gamertag/Microsoft account.

Its really simple, also you can have more than one email account on your Microsoft account.

Regards!

You're more than likely going to need to create another new email address that's not yet associated with any Xbox Live profile. Take a look over the information on the following link. It explains how you go about changing the email address for the gamer
tag that you want to use for Xbox Live. https://support.xbox.com/my-account/microsoft-account/change-email-sign-in-for-microsoft-account

Copy the link from the email and try pasting it in the browser.

Paste it in notepad - is it going through safe links?

Try pasting it in a browser - if it is blocked, are you using Defender? Since it looks liek Microsoft blocking it, it's more likely that than outlook.