Email Client OE still polls mail from deleted account?

Hi there, looking for some help if peeps can.

We have a specific issue typical to both Outlook and Express. Some time ago we had problems with emails asked provider to forward mail to alternative for short period of time.
Now resolved we went bak to as was. 1 machine 1 email account. Yet ever since despite assurances that the froward is removed we still get the other mail account (not wanted)previously deleted account on a random and consistent basis. How and where do we delete the settings that OE and Outlook are picking up the settings to download the other mail?

Running McAfee AV.

Thanks.