"Ghost"linked email address

When someone sends me a message to my me.com email account, they receive a message that their email was bounced--even though I actually receive their email. I believe the explanation for this is that my me.com account is still linked to an email address that is no longer active. However, I have gone to the Accounts preferences to see if the inactive email account is still linked, but it does not show up. Can someone help me solve this mystery?