Hello tqano,
The unfamiliar email is likely cached by the Microsoft Store, Xbox app, or Minecraft Launcher. Try this:
- Sign out of Microsoft Store and the Xbox app.
- Sign back into both using the Microsoft account that owns Minecraft.
- Open Minecraft Launcher.
- Select your username, then View all accounts > Switch Account > Sign in with a different account.
- Choose Use a different account and enter the correct email. A matching Q&A case uses this account-alignment process.
If the displayed email is genuinely unknown rather than an old account, stop and use the Microsoft account sign-in helper, as the account may require a security review.