Luminate Online now provides the 1024-Bit DKIM Email Signature in email deliveries for our clients. With this being the case, you do not have to worry about the Yahoo Domain Key record not found message with the DNS Checker tool. This checker is mainly to verify the SPF record that is configured with the sender domain. The results of the domain check doesn't really matter for the Yahoo! Domain Keys because we use our own DKIM signatures.