Internet Mail Service account is no longer valid

When the Active Directory Connector deletes your administrator accounts from your exchange 5.5 server (AND user accounts, recipients,mailboxes etc etc etc.) you may find that on reboot the server will not be able to start the Internet Mail Service and complains that the admin account is not valid. Not only do you have to change the username and password in the services on the server you also have to check that the IMC jas a valid administrator account as per the VERY helpful notes on eventid.net. As you might be able to tell we're not having a very good weekend.