I have the same issue with NTL and my ISP account. I get around it by using the ISP server (Waitrose) as the incoming server name and the outgoing as the cable modem mail server name (NTL) and setting the reply to to the name of my ISP account (waitrose). I have used this with Opera, Outlook and Outlook Express. Eudora must have an outgoing server name somewhere - I have used it in the past but that was ages ago.