I have several email addresses @btinternet.com. All of these successfully receive and all EXCEPT ONE successfully send. I have tried to send from the faulty one using webmail directly, and BT Yahoo states Messgage successfully sent, but it is never received (for these tests at another of my @btinternet addresses). I can send from all my @btinternet.com addresses except this one ... and I am trying directly on the BT Yahoo webpage, not via any client. What can I do??