Can’t access Webtv email account in Outlook

She transferred her account from webtv and now can't remember her password to access her email.  We have tried the "can't access account" several times but, she can't remember the security question, email addresses or any other required information needed to verify the account.  I have also tried to get a single use code sent to her phone with no avail.  Let me mention that that is how I was able to get into her other personal account.  What other options are there.  This is a business account and desperately needs to get into it.