It sounds like at some point you had added a second account to one of your inboxes. Do you know which account that would have been? You can sign into each account in webmail to check your settings by clicking the settings wheel, choosing All Settings in the menu and on the settings Panel, click Accounts on the left to see if a secondary account is listed under Your Accounts. If no account is listed on either, you can always add the second account back to one of them. Is there anything else I help with today?
