Yahoo mail admin

Is there a Yahoo mail admin on the list who could help me? We had a problem with the DNS for our domain a couple of days ago (somehow authoritative nameservers were changed at Network Solutions). Some Yahoo users are still unable to send mail to users, and some Yahoo users are sending fine. The problem is definitely affecting Verizon/Yahoo mail users but may be affecting others as well. I have a ticket open but it doesn't seem to be going anywhere.