Use the credentials in effect at the time that you last saved the file successfully. The email address does not have to be active.
Disconnecting from the internet may help -- won't hurt.
If you are using Sunset, after you get in, you can remove the existing credentials and optionally put a conventional password on the file. If you are using Money 2005, you will have to keep using the existing credentials going forward. You don't say what
version of Money you are using. If you file is from the US, you would have the option of converting to Sunset.