This article explains what to do if you cannot remember your original email ID when filling out the Directory change form.

On the Yahoo! Directory change request form, we ask for the email address you originally used to submit your request. If you can't remember it, you may submit the "Suggest a Change" form with a current email contact.

In the "Further Instructions" area, briefly explain your situation and give a business phone number. Please offer any information you may have regarding any possible email addresses of the person who originally submitted the request.