Can't mail out with BT Internet
Since my ISP BT has dumped Yahoo and now uses "mail.btinternet.com" as both incoming and outgoing addresses, I can' send mail on my iMac. I can on my iPad and on my PPC G4 under 10.5.8. Connection Doctor on my iMac says both addresses are connected but Mail reports "Cannot send mail with Server "mail.btinternet.com". Help please.