When I signed up for Gmail, this was sent to my secondary email address:
Congratulations on creating your brand new Gmail address, firstname.lastname@example.org. Please keep this email for your records, as it contains an important verification code that you may need should you ever encounter problems or forget your password.
You can login to your account at http://mail.google.com/
The Gmail Team
Verification code: xxxxxxxxxxxxxxxxx
Unfortunately, my secondary email address was hacked. I don't want the hacker to use one account to hijack another account.
So, how do I get a new verification code or how do I invalidate this validation code?