help,I'm going to lose my Firefox account

afew years ago, I signed up a firefox account with @yahoo.com.cn e-mail and password with 7 characters. Later Unfortunately, the @yahoo.com.cn email service closed down. Now, every time i try to log in addons.mozilla.com, i will get message "As part of our new password policy, your password must be 8 characters or more. Please update your password by issuing a password reset." But I can not reset my password via the old e-mail. How can I reactivate my account? Thanks. I can provide the original e-mail received from moziila when Registering my account as proof.