Hello! Hopefully, I'll be able to help you ^_^
Recently YahooBT has under gone some setting changes. Here's what it says on their site: We'll start moving email addresses (including any sub-accounts) from BT Yahoo email to our new email service, BT Mail, from Spring 2014.
https://home.bt.com/pages/email/index2.html-- This is the link to that info.
Attachments are only available to registered users.