Earlier this morning Yahoo and Yahoo UK & Ireland started experiencing problems with their RBL code. As a result, large number of messages have been rejected from our customer base to theirs. We are still working with Yahoo to resolve the issue, and a case is still open.
Users that had their email bounced would have seen returns in their inboxes. Please ask them to resend the messages. We will update the ticket when the issue is completely resolved.
Mail is flowing without issue at the moment, but the case with Yahoo is still open. We will update this site when the issue has been resolved completely.