I'm hoping that if I can import my list of Outlook contacts into BT Yahoo webmail it might stopping blocking emails from known friends. There appear to be no instructions for importing Outlook 2007 contacts into BT Yahoo/Talk21. I am following the instructions for earlier versions of Outlook, have checked the contacts are in the csv file I created, but I consistently get a response 'All 0 contacts successfully imported'.
Please help, many thanks.

You are approaching this from the wrong angle. You should be looking for ways from the Yahoo end. Try Yahoo's Help.

Thank you ScottGem - I tried asking Yahoo, but they said it was 'outside their field of expertise' !